public health

Lions And Tigers And…Deer? Oh My!

First it was bats and humans, then domestic cats and dogs, farmed mink, and big zoo cats; now gorillas, hippos, and wild deer that have been infected by the SARS-CoV-2 (CoV-2 for short) virus. Many of these animals have become ill and several have died of COVID-19, most recently three snow leopards in South Dakota and Nebraska zoos. This is quite a wanton virus.

Of course, before CoV-2 and COVID-19 were known to the world, we knew that bats, humans and a few other animals, notably civets and even camels, were ready hosts of several different strains of “‘rona” viruses. We also knew that domesticated animals are also susceptible to their own coronavirus diseases—in fact veterinary coronavirus vaccines have been in use for years. Humans are known hosts for several coronaviruses, including those that cause the common cold, as well as the viruses that cause SARS, MERS, and now COVID-19. And we know that humans often catch these germs from bats and other intermediate hosts as diverse as civets and camels. After we genetically identified CoV-2 and were able to follow its spread, we quickly noticed that domestic pets also could be infected. This was closely followed with news that seven big cats at the Bronx zoo had become infected, and that mink farms across Europe were hotbeds for CoV-2 spread between humans and the animals and back. In fact, mink farms became such a hotbed of CoV-2 zoonotic spread that a couple of European countries completely shut down mink farming and culled all their animals. Several US states have also sharply curtailed mink farming. PETA probably applauds.

More recently two snow leopards at the Lincoln, NE children’s zoo and one in a zoo in South Dakota died from COVID. The Lincoln zoo also had two infected Sumatran tigers who recovered after being treated with steroids and antibiotics to prevent secondary infections and pneumonia. How the animals were infected is uncertain, but the most likely scenario is that they caught the virus from a caretaker. The problem is, none of the caretakers tested positive for the virus. Bats? Something else?

Since April 2020, when a tiger tested positive at the Bronx Zoo, dozens of other animals in zoos around the world have caught COVID. This month, the Denver Zoo reported the first coronavirus cases in hyenas, and the St. Louis Zoo found eight positive cases among its big cats, including two snow leopards. Abroad, the virus has killed a lion in India and two tiger cubs in Pakistan. Big cats seem especially susceptible since three other snow leopards at the Louisville Zoo were infected last December, and another snow leopard tested positive at the San Diego Zoo in July. The virus doesn’t just infect our fuzzy friends either; two hippos, named Imani and Hermien, at a zoo in Antwerp recently tested positive for COVID-19. Zoo keepers were first alerted to a potential problem when they noticed that the colossi had “runny noses.”  One reckons that a runny nose for a hippo is a big deal. One also wonders who gets to dab that nasal maw in order to test for the virus.

In fact, zoo and domestic animal infections have become so prevalent that an animal COVID vaccine developed by Zoetis, a NJ-based veterinary pharma company and former Pfizer subsidiary, has been authorized by the USDA for experimental use. The Cincinnati Zoo, for one, has vaccinated  80 animals, from giraffes to apes, against COVID.

Deer too. Oh my! It is one thing for zoo animals to acquire COVID—their captivity makes it easy to limit their interaction with other animals and humans to prevent spread of contagions, and they seldom complain that their rights are being infringed when they are quarantined. However, COVID in wild animals is a different story, as we have seen with bats and how easily they transmit the virus to humans. Scientists now have evidence that CoV-2 also readily propagates in white-tailed deer. In fact, the virus is already widespread in cervids across the US, which likely has significant implications for the long-term course of this pandemic.

In September of last year, genetic analysis of the gene that encodes the ACE2 protein (i.e., the viral receptors expressed on many cells in the body) in many different animal species suggested that CoV-2 could easily infect deer (and several other animals too). A survey of white-tailed deer in the Northeast and Midwest found that 40% had antibodies against the CoV-2 virus, indicating prior exposure. Between April and December 2020, veterinarians at Penn State found active CoV-2 infections in ~30% of deer tested across Iowa. Then during the winter COVID surge in humans from Nov. 23, 2020, to Jan. 10 of this year, ~80% of the tested deer were infected. The prevalence of the virus in deer was 50 to 100 times greater than in Iowa residents at the time (and the deer reportedly did not wear face masks). The study, published about two months ago, indicates that white-tailed deer have become a permanent reservoir for CoV-2. While it is not fully understood how the virus entered the deer population, genetic sequence analysis of nearly 100 viral samples found that the variants circulating in deer matched the variants circulating in people. This suggests that deer caught the virus from people multiple times in Iowa alone. How that happens is not known since people usually do not have close contact with live deer. More concerning is whether viral variants arising in deer readily pass back to people.

Bottom line. Clearly, a lot of different animal species can catch Cov-2 and spread it. It is clear that people can spread coronaviruses to pets and other animals, but the FDA says that the reverse, animal-to-human virus transmission, is not common. But, it clearly happens as we have seen with this pandemic, and with many other viruses that cause SARS, MERS, AIDS, Ebola, flu, etc., that spread from animals to humans. The prevalence of CoV-2 infection in so many species of mammals, especially in animals that have close contact with humans, suggests that several animal species, not just bats, can serve as permanent reservoirs for the virus and the jump to humans is something that can happen over and over. This is not unprecedented. It is what we see with influenza, which is carried back and forth between the Northern and Southern hemispheres with migratory birds, in which different flu viruses shuffle their genomes to create the new strains of flu for which we have to vaccinate against each year. This animal reservoir for flu makes it next to impossible to eliminate influenza, and similar animal hosts for CoV-2 likely would make it nigh impossible to eliminate COVID too. I raised this specter some months ago in these pages when reporting that pet dogs and cats can carry the virus. Our furry friends represent a viral reservoir that is in even closer contact with people than bats, deer, and fortunately, hippos and leopards.

We also have to be worried about the CoV-2 virus mutating in the different animal species that harbor and spread it. We know that happens in bats, which makes it almost certain that new strains of the virus will arise in deer and dogs too. We have already seen this on mink farms in the Netherlands and Poland. Farmworkers passed the virus to captive animals where it spread, mutated, and then spilled back into humans. In fact, zoonotic transmission from animals to humans probably happens thousands of times a year. Researchers from the EcoHealth Alliance and from Duke-NUS Medical School in Singapore, estimate that each year many people are newly infected with SARS-related coronaviruses. Many may get sick, but there are many reasons why most of these infections never grow into noticeable outbreaks (for example see my earlier blog post about unusual respiratory infection clusters in China and Los Angeles just before COVID). The researchers also created a detailed map of Asian habitats of 23 bat species known to harbor SARS-related coronaviruses then overlaid it with data on where humans live to create a map of potential infection hot spots. They found that close to 500 million people live in areas where bat-to-human transfer is likely, and this risk is highest in southern China, Vietnam, Cambodia, and Indonesia. Other surveys done before COVID-19 showed that many people in Southeast Asia harbor antibodies against other SARS-related coronaviruses. Blending these data with data on how often people encounter bats and how long antibodies remain in the blood, the researchers calculated that ~400,000 undetected human infections with these viruses occur each year across the region.

That is just for bat-to-human transfer in Southern Asia. It now looks like we will have to also concern ourselves with zoonotic coronavirus transfer from Buddy and Bambi too.

For this reason, researchers are working to develop a universal coronavirus vaccine that will be effective against most viral strains and variants. I will write about this soon. Stay tuned.

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Lessons for COVID Vaccinations And Herd Immunity From Influenza And Rubella

Note: The following is modified from the blog post, “Rubella: We vaccinate for far less,” by Katelyn Jetelina, MPS, PhD who is an “epidemiologist, biostatistian, professor, researcher, wife, and mom of two little girls.” She writes a blog entitled, “Your Local Epidemiologist.”

 “Those who cannot learn from history are doomed to repeat it.”

 George Santayana

 

In the US, more than 300,000 kids aged 5-11 have been vaccinated with the Pfizer COVID-19 vaccine, which has proven that the vaccine is safe and can benefit some kids. It prevents infection, COVID-19 disease, death, long COVID-19, and keeps kids in school. Admittedly, only a few kids develop serious COVID disease and fewer have died from it. Most infected kids only have mild, if any, symptoms. Vaccine skeptics use this fact to stridently argue against childhood COVID vaccines. So, why are we pushing to vaccinate children who rarely get seriously ill?

There are two reasons why we vaccinate anyone. The first reason is to protect the vax recipient from the disease; this is an individual-level benefit of the vaccine. The second is to protect a larger population by trying to retard disease spread; this is a population-level benefit of vaccines that is better known as herd immunity.

But, anti-vaxers only focus on the fact that childhood vaccines provide little individual-level benefit to children and wholly ignore the larger population-level benefit of the vaccines. As I have written before, vaccinating children who are at low risk for serious disease is still very important for reducing viral spread in order to  prevent more dangerous viral mutants from emerging. It also is important for reducing infection and disease in more vulnerable people in the population. It is these population-level benefits that are the most important reason to vaccinate low-risk children. Vaccinating children for a population-level benefit, rather than for individual-level benefit, is not at all new and is a very acceptable practice. Here are a couple of examples.

Influenza: A few decades ago, Japan mandated flu vaccines for all school kids. That vaccine slowed the spread of flu in schools leading to many fewer student illnesses and absences. More significantly, vaccinating all school kids also caused a sharp drop in flu deaths in older people like school teachers and staff, parents, and grandparents who have close contact with the kids.

Kids are walking incubators for respiratory viruses and readily spread their germs to others. Infected children essentially are virus vectors much like mosquitoes are vectors for malaria and yellow fever. Therefore, in Japan, the flu vaccine effectively shut down a major vector of influenza infection for at-risk older people. That is an undeniable and important population-level benefit of vaccinating school kids against the flu.

Rubella: Now, let us take a deeper dive into rubella, or German measles, and its vaccine, which is the “R” in the MMR shot. It is especially enlightening to compare the natural history of rubella to what we are learning about COVID-19.

Both COVID and rubella are caused by airborne viruses that spread when infected people cough, sneeze, or even talk. As with COVID, rubella symptoms in children are quite mild. They include its tell-tale measles-like rash, sore throat, low grade fever, mild pink eye, and general discomfort. But, about 25 to 50% of infected children will not experience any symptoms. Likewise, many CoV-2 infected kids also do not develop symptoms. But, asymptomatic kids infected with either rubella or CoV-2 readily spread their viruses to friends and family; hence, they can be significant vectors delivering both viruses to people at-risk for serious disease.

Over the last two years, we have learned that COVID mostly (with significant exceptions) causes serious illness and death in older people or for those with certain other health conditions. Similarly, while rubella only causes mild disease in most children, it is incredibly dangerous for developing fetuses. A woman infected with rubella during the first 3 months of pregnancy has a 90% chance that the fetus either will not survive or will develop Congenital Rubella Syndrome (CRS), characterized by deafness, blindness, heart defects, and/or severe brain damage. In the early 1960s, a rubella outbreak began in Europe and spread to the US. In 1964-65 ~12.5 million total cases were reported in America affecting nearly 50,000 pregnancies. More than 11,000 of the infected mothers miscarried, or delivered still-born babies. Of the >20,000 infants born alive to infected mothers, the majority had severe illnesses: 2,100 died shortly after birth, 12,000 were deaf, 3,580 were blind, and 1,800 had permanent mental disabilities.

The rubella outbreak proved hard to contain because, as with COVID, infected asymptomatic people make it hard to know when someone is spreading the virus. Rubella also is just as contagious as COVID. Both viruses have an R0 = 6-7 meaning that each infected person will infect, on average, 6-7 other people. For comparison, flu’s R0 = 2-3, which means it is about half as contagious as the other two viruses. It, therefore, is not surprising that like rubella, the COVID outbreak is proving hard to contain.

Soon after the 1960s rubella pandemic began, a safe and effective vaccine was quickly developed and approved for use in Europe and North America (this is reminiscent of the quick development of the COVID vaccines). Early on, there was a robust international debate on who should get the rubella vaccine. There were two schools of thought:

  1. Despite the fact that rubella only caused mild problems in kids, some proposed vaccinating all children hoping to provide indirect population-level protection for pregnant women and their at-risk fetuses.
  2. Others argued that because children were only minimally affected they should not be subjected to the vaccine and that only women of childbearing age should be vaccinated. This, proponents argued, would more specifically protect those most at risk.

Ultimately, it was found that countries that chose #2 were not able to sufficiently reduce the virus, because it still spread unfettered among children. This strategy did not reduce the rates of CRS. Eventually, option #1, vaccinating low-risk children (like what we are moving toward with the COVID vaccine) was adopted world-wide. Vaccination rates of school kids reached ~85% in the US, which last experienced a serious rubella outbreak in 1995. In 2004, transmission of rubella was eliminated in the United States and in 2015, it was eliminated in all the countries of North and South America.

Soon, the MMR vaccination was mandated for children in all 50 states. It is important to realize that these mandates were not to protect kids from the mild disease but to protect the at-risk population, or fetuses. In other words, we vaccinate kids against rubella not so much to protect them, but to provide a significant population-level benefit to others.

Today, because of broad rubella vaccination of low-risk children, we see an annual average of just 10-15 cases of CRS in the US that are traced back to international travel to countries with poor rubella vaccination rates. In contrast, in countries with low vaccination rates, about 120,000 children are born each year with severe CRS birth defects and even more die in utero.

Bottom Line: This country, and indeed all of the Americas and most of Europe came together to eliminate endemic rubella through broad population-level vaccination programs targeting low-risk groups responsible for spreading the virus to the high risk population. Japan saw the same effect with influenza. They focused on broadly vaccinating a low-risk population (school kids) and saw great benefits in the high-risk older population. As we approach a broad COVID vaccination strategy that includes giving the shot to low-risk children, it very likely will have a population-level benefit and help protect those most at-risk for serious disease.

It is important to note that the population-benefit conferred by the COVID vaccine also applies to all of us and not just to children. When we are vaccinated, not only does it protect us, it also provides significant protection to at-risk people around us. That, in fact, is called “herd immunity.”

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The History Of Vaccine Mandates In The US

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As employers and the President are pushing vaccine mandates because too many have refused them, voices are crying out for their perceived rights saying “my body my choice.” They do not like their bosses or the government telling them to get vaccinated. This is a clash between individual rights and public health measures designed to save lives and to protect the larger community. Who gets to make the key decisions? How far can the government and employers go? Do individual rights trump community safety?

On Sept. 9, Biden announced the most sweeping vaccine requirements in American history, ordering that businesses with 100 or more employees ensure that all their workers are either vaccinated or get tested weekly for the coronavirus. The new rules also require vaccinations for federal workers and for federal contractors, as well as for workers at healthcare facilities that receive funding from Medicare and Medicaid. This will affect about 100 million people.

The authority for these government mandates, claims Biden, is a 1970 federal statute that gives the Secretary of Labor authority to issue a six month Emergency Temporary Standard (ETS) to protect workers from “grave danger from exposure to substances or agents determined to be toxic or physically harmful.” His move has triggered a political and legal battle, with many Republican governors vowing to fight the mandates in court. The mandates raise several new questions regarding this vague statute: Is a virus a “…toxic or physically harmful substance?” Does COVID-19 present a “grave danger?” Has the executive branch exceeded its authority in offering a solution to a problem previously reserved to the states? Do these mandates violate the 14th Amendment by depriving workers of their personal liberties? It is important to note that Biden’s mandates do not actually make vaccines compulsory: The government may levy a fine or forbid a child from attending school, but no American will be forced to get an unwanted jab. This has not always been the case.

There are historical precedents for vaccine mandates and even for forced vaccination.

In February 1991, five Philadelphia children died from measles, a disease that was mostly eradicated in the US, due to vaccination. Measles once sickened millions of kids, each year hospitalizing ~50,000 and killing close to 500 before a successful vaccine was developed in 1963. After that, cases dropped dramatically as all states mandated measles shots for school children. Vaccine hesitancy and resistance were rare because people saw the tangible success of the measles vaccine.

But, in Philadelphia that winter of 1991, the serious cases of measles came from a single source, a church cult that rejected “…all means of healing apart from God’s way.” Church members took no medicines, owned no thermometers, and saw no doctors. Rejecting all birth control, they raised large families in close quarters, a recipe for the measles epidemic, which they cooked. Trying to contain the threat to the rest of the city, officials worked through the courts to gain access to the homes of the congregants and received the authority to vaccinate the children against the wishes of their parents. In this public health emergency, defending the parents’ anti-vax actions was close to impossible. Even the ACLU took a pass.

Vaccine mandates even appeared during the Revolutionary War. George Washington mandated that all his troops be immunized against smallpox, even against their will. He described smallpox to Virginia’s Governor Patrick Henry as “more destructive to an Army in a Natural Way, than the Enemy’s Sword.” As I wrote earlier in these pages, smallpox had doomed the Colonial Army’s assault on Quebec in 1775, and it threatened Washington’s main force. Washington’s mandate proved a brilliant gambit and smallpox largely disappeared from the ranks. Some historians point to the mandate as a major factor in winning the war against the Brits.

During that war, smallpox vaccination entailed a primitive vaccination procedure known as variolation. That involved opening a lesion from an infected person and scraping its contents into the arm of a recipient. It was effective, but the vaccinated person became quite ill for a couple of weeks, and about 3% of them died from the pox. Later, in 1796, the English scientist Edward Jenner discovered a much safer method of immunization using cowpox, a virus similar to smallpox that did not cause significant disease in people. But the new smallpox vaccine got a mixed reception in the US as some resisted it for reasons of personal safety based on the variolation experience. They rationalized, “what good could possibly come from polluting the body with dangerous foreign matter?” Or, “Why challenge the plans of the Creator?” Still, Jenner’s vaccine was a clear improvement over variolation and drove a steady decline in smallpox outbreaks throughout the 19th century. States began passing laws mandating smallpox vaccinations for school children, and some forcibly vaccinated prisoners, paupers, and orphans.

In 1905, the issue of vaccine mandates reached the Supreme Court in the seminal case of Jacobson v. Massachusetts. Henning Jacobson, a Lutheran pastor in Cambridge had defied a city ordinance requiring smallpox vaccinations during an outbreak. He refused to pay a $5 fine so he was arrested. Jacobson posited that “healthy and law-abiding” people like himself (even though he was disobeying the law at the time) posed a minimal danger to the community. He argued that even if his refusal to be vaccinated led to him spreading the smallpox virus, the only victims would be others “who failed or refused to be vaccinated.” In other words, he reasoned that it would be ok to not get the vax because the vaxed would be safe, but wholly ignored the rights to safety of those who were not vaxed. 

It is an argument that is repeated today about the CoV-2 vax. Using modern science that was not available in the early 20th century, experts have repeatedly refuted this argument, explaining that many people who want the vax cannot be fully vaccinated because they are immunocompromised, or allergic to the vaccine’s contents, or do not have access to the vaccine. Also, we now know that the more RNA viruses, like the coronavirus, are allowed to spread, the greater the chance more deadly variants can appear. Jacobson’s contention that the decision to vaccinate solely belongs to the individual, not to the state, employers, or to medical authorities remains a central tenant of today's anti-vaxers.

The Supreme Court disagreed with Jacobson. The majority opinion, written by Justice John Marshall Harlan, asserted that “the liberty secured by the Constitution does not import an absolute right in each person to be at all times, and in all circumstances, wholly freed from restraint.” Rather, he argued, the Constitution rests upon “the fundamental principle of the social compact…that all shall be governed by certain laws for the protection, safety, prosperity and happiness of the people, and not for the profit, honor or private interests of any one man, family or class of men.” Jacobson had not only broken the law, the court suggested he also had violated the principle upon which a well-ordered society depends. We are not wholly independent the court ruled. The greater good of the community can trump individual rights.

Using Jacobson as precedent, the Supreme Court in 1922, upheld a local ordinance in San Antonio requiring proof of smallpox vaccination for people entering “public schools or other places of education.”  

Later, during World War II, the US military made vaccines mandatory for a host of diseases, such as typhoid, yellow fever and tetanus, and it still mandates certain vaccines for troops in certain deployments. Soon after the war very successful vaccines were developed against several childhood diseases like polio, measles, mumps and chickenpox. Guided by the Supreme Court’s ruling in Jacobson, all 50 states put laws on the books mandating many of these vaccinations for school children. Even today, many school districts and colleges mandate certain vaccines for students and staff. Hospitals, too, often mandate certain vaccines for their staff. Until lately, vaccine mandates have not generated much angst and anger.

Why is this? Perhaps vaccines have done their job too well: Many of them have erased the tragic evidence of why they were needed in the first place. The world no longer deals with small pox, thanks to the vaccine. Almost no one in this country has seen someone ravaged by polio, or a child hospitalized with measles, or who lost his hearing due to chicken pox, all thanks to vaccines. Yet, now with COVID-19, anti-vaccine anxieties have found their way into the political mainstream, especially among conservatives. An estimated 80 million American adults remain unvaccinated against COVID and represent potential factories for producing the next deadly coronavirus variant, which is very preventable.

As I have addressed before in these pages, many factors fuel resistance to the life-saving shots, including doubts about their quick development and their possible long-term effects. But a growing distrust of professional expertise, including medical science, has also played a role, which is unwarranted. Who are you going to believe, a medical scientist like me with nothing to gain in the debate (except the safety of my friends, family, and self), or someone who read a web post from folks who are selling nostrums they claim will protect you, like Dr. Steve Hotze, or from one of America’s Frontline Doctors whose web site claimed that gynecological problems were caused by having sex with demons? Do you jump on the side of those who tout that their individual freedoms have been abridged, but who do not consider the freedoms from disease of the greater community, and whom the courts already have decided against?

Almost 300 years ago, Benjamin Franklin struggled over whether to have his sons variolated against smallpox. In his “Autobiography,” he worried that well-meaning people were tragically misjudging the calculus between the risks and benefits of the procedure, as he had once done, with a tragic result. He wrote, “In 1736, I lost one of my sons, a fine boy of four years old, by the smallpox….I long regretted bitterly and still regret that I had not given it to him by inoculation. This I mention for the sake of the parents who omit that operation, on the supposition that they should never forgive themselves if a child died under it; my example showing that the regret may be the same either way, and that, therefore, the safer should be chosen.”


The Long Haul, Part 2: What Is Long COVID?

In the 1890s one of the biggest pandemics in recorded history, known then as the “Russian flu”, swept the world and killed one million people (for perspective, that is out of a world population about ¼ of today’s population). That “flu” is now thought to have been a novel coronavirus. Like the current coronavirus, SARS-CoV-2, the Russian “flu” was a new human pathogen so few people had any natural immunity to it and it was quite lethal. Not only that, but as the pandemic waned, it left in its wake a global wave of long-lasting neurological problems in the survivors. A similar long-lasting post-acute disease wave followed the next big pandemic, the “Spanish” flu of 1918 (which really was due to the influenza virus). The common symptom following the Spanish flu was lethargy so bad that in Tanganyika (modern-day Tanzania), for example, it caused a famine because people were too debilitated to pick the harvest. Other viral outbreaks, including SARS, MERS, and Ebola, also have been associated with long-term sequelae in survivors. However, today’s long COVID complications are far more common and far more variable than the persistent symptoms following these other viral pandemics. The variety of unrelated long COVID symptoms has flummoxed doctors hard pressed to diagnose and, hence, treat the constellation of chronic problems that appear in each patient.

As I wrote in Part 1 of this series, a wave of what has become known as “long COVID” is emerging in many people who have recovered from the acute disease. A recent review chronicling the effects of long COVID reported that “long haulers” commonly experience fatigue, sleep problems, and joint and muscle pain long after their bodies cleared the virus. Other symptoms range from the mundane to the bizarre: brain fog, shortness of breath, fatigue, tremors, tooth loss, racing heart, glaucoma, and diabetes among others. Long haulers are also at a significantly increased risk of dying months after infection. A large study found that after surviving acute COVID-19, patients had a 59% increased risk of dying within six months after their initial diagnosis. This translates into an extra eight deaths per 1000 patients. Thus, the consequences of the acute disease itself are just the tip of the iceberg.

Because the official definition of the chronic problem is fluid, we are still learning what this new malady is. A UK study published last December simply defined the syndrome as a collection of symptoms lasting for more than 28 days after initial diagnosis. However, another British study as well as Britain’s National Institute for Health and Care Excellence vaguely and broadly define long COVID as “signs and symptoms that develop during or after an infection consistent with COVID-19, and that continue for more than 12 weeks and are not explained by an alternative diagnosis”. It does not specify a list of what the symptoms are.

But, there are many. A global survey tallied 205 different symptoms across 10 different organ systems that can persist after COVID infection has cleared, including those affecting the heart, lungs, gastrointestinal system, muscles, and joints. There also are frequent neurological and neuropsychiatric symptoms as highlighted in Part 1 of this series. A sufferer typically has several of these problems at a time (14 different symptoms on average), with the most debilitating usually being one of three: severe breathlessness, fatigue, or “brain fog”. Other common symptoms included compromised function of the lungs, heart, and kidneys sometimes requiring transplantation. There also have been skin rashes, and newly diagnosed diabetes.

What exactly is long COVID? About the only thing we can say with any certitude at this time is that long COVID exists but is not easy to describe, possibly because it really is more than one malady. The only constant between different long COVID patients with different symptoms is that the conditions are a collection of varied symptoms that persist long after the acute disease subsides, which sounds as vague as the British definitions described above. Long COVID clearly represents a new health malady or maladies since it is not generally found in uninfected people, but is common in COVID survivors; yet not all COVID patients experience it. Long COVID can affect any post-COVID patient at any age, but it mostly presents in middle-aged people and seems to slightly prefer women. Even people with asymptomatic CoV-2 infection can have late arising effects that fit the profile of long COVID.  Multiple studies have shown that infected people who do not get acutely ill can still show irregular lung scans, for example. One such study found that nearly 60% of people with asymptomatic infection showed some lung inflammation in CT scans. Other studies have shown that young people with asymptomatic or mild infections can have long lasting cardiac issues, while others show signs of small blood vessel damage.

Some of these symptoms can be similar to other recognized, if not fully understood chronic problems, such as chronic fatigue syndrome (CFS), which is one of the most common complaints that long haulers have. CFS remains a mystery malady with an unknown cause, but it often follows a viral or bacterial infection. It is, therefore, possible that long-COVID CFS-like problems might be no different from classic CFS. It also is possible that CFS-like long COVID symptoms are not at all related to what is recognized as classic CFS, and they are simply different illnesses with similar symptoms. Time and research will tell.

Broadly speaking, there are three types of long COVID patients, according to one NIH scientist. The first are generally characterized by “exercise intolerance”, meaning they feel out of breath and exhausted from even mild physical activity. The second are characterized by cognitive complaints like brain fog and/or memory problems. The third type experiences problems with the autonomic nervous system, which controls things like heartbeat, breathing and digestion. Patients in this group suffer from symptoms such as heart palpitations and dizziness. Impairments of the autonomic nervous system are known as dysautonomia, which is an umbrella term for a variety of syndromes. Physicians treating long-COVID patients say there has been a marked increase in dysautonomia since the pandemic began. A rehabilitation doctor at Mount Sinai Hospital, in New York, says that roughly 80% of people who show up at his long COVID clinic have dysautonomia of one type or another.

Not only do long COVID patients suffer chronic debilitation, they also are at increased risk of dying. One of the largest studies of Covid-19 “long haulers” found that COVID survivors had a 59% increased risk of dying within six months after contracting the SARS-CoV-2 virus. The excess mortality translates into about 8 extra deaths per 1,000 patients. Thus, the pandemic’s hidden toll is that many patients require readmission, and some die, weeks after the viral infection abates.

What causes long COVID? What causes the myriad of symptoms lumped under the long COVID umbrella are being studied, but it seems that not all are actually caused by the CoV-2 virus. Based on what we have gleaned from observations of a few million long COVID patients around the world, the focus is on three possible biological explanations. One is that long COVID is due to a persistent viral infection. A second possible cause could be an autoimmune disorder. The third possibility is that it is a lingering consequence of tissue damage caused by inflammation during the initial, acute infection.

Supporting the first hypothesis that the infection persists even after COVID disease has passed is that some patients very slowly clear the virus completely. The virus or its remnants persist along with the long lasting symptoms. These patients are not infectious so it could be that they harbor some altered form or fragment of the bug which does not replicate, but is nevertheless making some viral product that their bodies are responding to. This is known to occur with other viruses, including measles, dengue and Ebola. RNA viruses are particularly prone to this phenomenon, and CoV-2 is an RNA virus. Direct proof of this hypothesis is lacking, but pertinent clues abound. A study published recently in Nature showed that some people had traces of CoV-2 proteins in their intestines four months after they had recovered from acute COVID-19. Viral products from CoV-2 have also been found in people’s urine several months after their recovery. All this is circumstantial evidence, to be sure, but viral persistence is consistent with long COVID in certain patients.

The second hypothesis, that long COVID is an autoimmune disease, holds that the virus causes something to go awry with the immune system inciting it to attack some of the body’s own tissues. Some evidence backs this idea, too. The immune system is a complex, tightly regulated machine designed to discriminate between your own cells and foreign entities such as viruses. Sometimes this ability to distinguish self from non-self fails and an immune response is generated to one’s own tissues. Some patients suffering from long COVID have badly behaving macrophages, which are immune cells responsible for gobbling up foreign invaders and displaying them to immune cells inciting them to make antibodies or to kill infected cells. Other long COVID patients exhibit abnormal activation of their B-cells, which churn out antibodies against the pathogen that can sometimes cross-react with the body’s own cells causing complications. Since antibodies circulate for several months after an infection, it makes sense that this could cause problems months after recovery from the disease. Again, this evidence is circumstantial, but consistent with the observations in some long haulers.

The third hypothesis about the cause of long COVID holds that the body’s inflammatory response during the acute illness causes long-term damage to cells and tissues leading to chronic inflammation. This sometimes happens with other viral diseases, but it could be particularly likely with COVID-19 since out-of-control inflammation, caused by a cytokine “storm” is a common hallmark of severe cases of acute illness. One guess is that the inflammation damages parts of the autonomic nervous system, or that the virus might damage the cells that line blood vessels, either by infecting them directly and/or via inflammation from the immune response. This could change the way blood flows to the brain and other organs, and may thus explain the brain fog and other organ failure that is sometimes seen. This too remains circumstantial, but consistent with current observations in certain patients.

Bottom line: Long COVID probably embraces several different chronic conditions with different causes. Studies to investigate each of these possibilities are under way.

We will see.


HIV And Coronaviruses: A Bad Combo

Africa is the continent least vaccinated for COVID-19 and it also has been where several CoV-2 variants have arisen: Beta in South Africa, most recently C.1.2 (not yet given a Greek letter designation) also from South Africa, and Eta in Nigeria. A possible reason for the appearance of these variants is because Africa is also home to the most immunocompromised people. HIV is common in Africa and tuberculosis is rampant on the continent.

One HIV-positive woman in South Africa was reported to carry active CoV-2 infection for 216 days, during which time it mutated 30 times according to Tulio de Oliveira, who runs gene-sequencing centers at two South African universities. This is concerning since South Africa has the world’s largest HIV epidemic. It is estimated to have 8.2 million people infected with HIV. While most of these take antiretroviral drugs, which keep the virus at bay, many do not. And neighboring countries, Botswana, Zimbabwe, and Eswatini also have very high HIV infection rates. The burden of HIV, TB and other chronic diseases is higher in these countries than in other countries around the world due to extreme poverty and poor health care for millions of Africans. When these people also become infected with CoV-2, they grow and shed the virus longer than someone with a good immune system and good health care. That means that the virus has longer to mutate in an infected, immunocompromised person.

In wealthier countries in the West, a rich debate is ongoing about whether to add another shot (booster) to already vaccinated people. One of the biggest arguments against this is that those booster vaccines are needed much more in poorer, and woefully under-vaccinated countries, such as those in Africa. The concern is that our boosters come at the expense of basic immunization of these impoverished countries, which facilitates the generation of troublesome viral variants. On the other hand, if CoV-2 is running rampant because the health care infrastructure in these countries is not up to delivering those vaccines, maybe it would be better making sure that richer countries are as protected as possible.

These are the proverbial two horns of a dilemma. Which horn would you choose?


Evidence That Facemasks Prevent COVID-19

As Delta proliferates while the world tries to get back to normal, requirements to wear facemasks in public are also proliferating. The mask mandates are causing no end of consternation in certain segments of the population, which like to claim that there is no evidence that they prevent disease. Their evidence behind this claim is weak and usually boils down to claiming that the virus is similarly prevalent in states with and without mask requirements. For instance, they like to point out that California, with strict mask mandates, has about the same rate of COVID-19 as Florida, which does not have widespread mask mandates.

But, this is not a strong argument. In research, we carefully design studies to compare experimental vs control groups that are as similar as possible in every way except for the variable we wish to test. In other words, we try to isolate the test variable by making all else as equal as possible. This goal for a well-controlled experiment falls apart when comparing California to Florida—they are very different. Differences include age, population and housing density, reliance on public transportation, climate, humidity, and demographics. All of these variables, if not controlled for, will confound the relationship between mask policies and COVID-19 outcomes because each of these variables also affects the spread of disease.

However, comparing counties within a state helps address at least some of these confounding factors since counties within the same state are generally more similar than two different states at opposite ends of the country. Researchers have done just this in Kansas where 21 counties implemented a mask mandate while the others did not. Counties with a mask mandate saw a significant drop in COVID-19 while counties without a mandate saw a 100% increase in new cases during the period of evaluation.

More recently, the ABC Science Collaboration, a partnership between health scientists, K-12 schools and community leaders, in North Carolina collected infection data from >1 million students and staff members between March-June 2021. More than 7000 students and staff caught COVID-19 during that period and contact tracing showed that >40,000 people had close contact with the infected ones. Very few of these close contacts caught the virus and all of them, the infected cases and their close contacts, wore masks. In other words, in schools with mask mandates, there were no outbreaks despite initial COVID infections. And schools are ripe for creating super-spreader outbreaks.

A systematic review and meta-analysis published in The Lancet, examined the efficacy of face masks in reducing the transmission of different coronaviruses (SARS, MERS, and COVID-19). The authors evaluated 39 studies and found that face masks significantly reduced the risk of coronavirus infection compared to no mask wearing.

An article published in the Proceedings of the National Academy of Sciences in January 2021 also reviewed the evidence supporting the use of face masks and similarly concluded that near-universal adoption of non-medical (i.e., cloth) face masks in public could significantly reduce the R0 value of the virus, which is a measure of how well it spreads. In fact, I earlier discussed in these pages a similar finding by British researchers who concluded that widespread mask-wearing could substitute for herd immunity.

There are several other published studies that reach similar conclusions about facemasks. But, perhaps the most comprehensive study was just reported by researchers at Stanford and Yale. It involved a method called cluster randomization where villages in Bangladesh were randomized to get facemasks or not. It involved some 340,000 people in 600 villages. 100 villages received cloth masks and 200 villages received surgical masks. The remaining 300 villages did not receive any intervention to increase mask wearing. The results showed that increased community masking decreased COVID-19 disease in these real-world settings. Surgical masks performed better than cloth masks at reducing COVID-19 disease, though cloth masks were definitely better than no masks.

On a final note, let me reissue my earlier challenge to anti-maskers: If you really think they do not prevent infection, then next time you have surgery, invite the surgical team to throw the masks out when they open you up.

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Delta: It is always better to prevent than to treat!

Previously in these pages I wrote that it was important to vaccinate kids as well as all adults, even though kids generally do not get very sick from CoV-2 infection. I also opined that it was important to get vaccines to third-world Asian and African countries that lack them. I further lamented the inability of one of the world’s leading vaccine manufacturing countries, India, to vaccinate its own population. The common reason for these exhortations in separate blog posts was the need to suppress the spread of the virus as much as possible, which I submit is just as important as protecting people from COVID-19 disease. We need to try to suppress the emergence of new viral variants since they could be more deadly and even cause significant disease in younger, healthier people. Such variants could also learn to ignore vaccine immunity and set us back to square one fighting the pandemic. As viruses replicate, they make random genetic mistakes in copying themselves. By chance, some of those mistakes can potentially make the virus more infectious or deadly. It is crucial to slow virus spread as much as possible with vaccines and social distancing measures in order to reduce the chance of such new, more deadly variants developing.

At this juncture, let me introduce the Delta variant and say, “I told you.”

Delta is more infectious. The Delta variant was first detected in October 2020 in India during that country’s long, strict shutdown. As I earlier reported, it then exploded across the country after those restrictions were lifted the following March in time for huge national  election rallies and a major religious holiday that brought hordes of Hindu worshippers to the banks of the Ganges. Delta quickly overtook previous iterations of the virus in India and has now spread to more than 100 countries, meaning that it has a significant advantage over other variants in the race to infect people. Delta was first detected in the U.S. in March and by mid-July accounted for 83% of all U.S. cases. As of the end of July, the Delta variant had caused at least 92% of the new infections in the United States, according to covariants.org, a research firm in Bern, Switzerland. The Johns Hopkins University tracker reported that daily US COVID-19 cases rose from just over 13,000 at the end of June to almost 131,000 in mid-August. almost all of which are due to Delta.

Delta has kept some of the most successful mutations found in earlier variants that first appeared in England and South Africa, but it also contains new genetic changes that, together, enable it to spread faster. In an earlier blog post, I talked about the R0 value, or the measure of a virus’s ability to spread. For seasonal flu, R0 is about 2, meaning that on average, an infected person will infect two others. For the original SARS-CoV-2, R0 was ~4, which means that on average, an infected person infected four others. Now, according to the CDC, the Delta variant has an R0 of 8-9 meaning that an infected person will, on average, pass the virus to 8-9 others. Therefore, Delta is about 4-times as contagious as the virus first identified in Wuhan. Clearly, viral variants are trending toward increased ability to spread. We can expect that the virus is not finished evolving and could become even more contagious.

How do the mutations make Delta more infectious? Research now shows that Delta has an incubation period of four days, which is the time it takes to begin spreading after infection. The original virus incubated for six days. Thus, people are becoming contagious sooner. Also, people infected with Delta are found to carry >1200-times the viral load compared to prior virus iterations. People carrying more virus pump more virus into their environment making them more infectious. With earlier variants, conventional wisdom held that you needed to be around an infected person for about 15 minutes in order to catch an infectious load of the virus. That wisdom now holds that one only needs to be in the presence of a Delta-infected person for 1-5 minutes before becoming infected. 

Some vaccinated people can also be infected and spread Delta. With any viral vaccine, the hope is that the vax will not only prevent disease, but also retard the spread of the virus, ideally reducing its R0 value to <1. When an infected person only spreads the virus to fewer than one other person, the epidemic/pandemic would be nipped in the bud. So far, the vaccines have done a pretty good job reducing the spread of the virus; however, the Washington Post recently obtained an internal CDC document  citing a combination of recently obtained data from outbreak investigations and other studies showing that vaccinated individuals can sometimes be infected with Delta and transmit the virus as easily as those who are unvaccinated.

The data showed that vaccinated people infected with Delta sometimes had viral loads similar to infected and unvaccinated people. These data came from a July 4 outbreak in Provincetown, MA where 127 vaccinated people were infected with the Delta variant in the superspreader outbreak and they appeared to carry as much virus as unvaccinated people who also became infected. Vaccinated people with breakthrough infections only showed mild symptoms including cough, headache, sore throat, or fever. Four were hospitalized and no deaths were reported. On July 3, the day before the event, the Massachusetts Department of Public Health reported a two-week average of zero COVID-19 cases per 100,000 residents. By July 17, after the superspreader event, that number rose to 177 daily cases per 100,000. The ability of Delta to infect some vaccinated people and spread from them has been further confirmed by research published by Public Health England.

This is the reason why the CDC just recommended that all people, including vaccinated people, again don face masks when in public indoor spaces. Fortunately, the virus does not cause significant disease in this population meaning that the vaccines still protect from serious disease.

So far.

Vaccine efficacy. The CDC reports that even though the current vaccines do not fully protect against breakthrough infections, such infections only occur in about 0.1% of the 140 million vaccinated people and they still reduce the risk of severe disease 10-fold and they still reduce the risk of breakthrough infection three-fold. That is the good news.

The disappointing news is that real-world studies of vaccine efficacy indicates that the current vaccines have become somewhat less effective at preventing infection from the Delta variant than they were against earlier versions of the virus. One way to measure a virus’s ability to evade vaccines is to take antibodies from vaccinated patients and combine them with the virus in the lab, then measure how much of the virus is neutralized, or prevented from infecting cultured human cells. Dr. Akiko Iwasaki, an immunologist at Yale University, and colleagues used this technique to compare how well different coronavirus variants can withstand vaccine immunity. Iwasaki found that Delta was better at evading neutralization than earlier versions of the virus. More concerning, however, is that they also found that two other variants, Beta, first found in South Africa, and Gamma, from Brazil, were even more adept at avoiding antibody neutralization. It appears that viral mutations are being gradually selected for their ability to bypass the immunity conferred by the current vaccines. That trend is worrisome.

Other reports coming in now indicate that the early vaccine efficacy of ~95% has dropped to 70-80%. This value represents the protection a vaccinated person can expect when exposed to the virus. The increase in the number of vaccinated people who become infected suggests either that that their immunity is fading over time, or that, as mentioned above, Delta is learning how to avoid vaccine immunity. Or both. As I wrote earlier, the initial antibody response to a vaccine naturally decays over time but immunity is usually sustained via memory immune cells which serve as quick-response sentinels to subsequent exposure to the pathogen. Memory immune cells were found in another study to be robust six months following mRNA vaccination and able to efficiently respond to the known viral variants. This indicates that long-term immunity remains strong and suggests that Delta has begun to learn how to avoid vaccine immunity.

Stay tuned.

Severity of Delta disease. In India, the Delta variant caused more severe and faster illness than earlier variants, and now in the US, Delta also seems to more readily cause significant disease and do so in younger people. Currently, teens 16-17 years old are now seeing the highest rate of COVID-19 cases among all age groups in the US. That is up from a rate of 48 per 100,000 on July 10, to 200 per 100,000 people on August 14. As Delta now accounts for >95% of new COVID-19 infections and hospitalizations in the US, doctors on the front lines are reporting anecdotally that unvaccinated people in their 20s and 30s are becoming more critically ill, and faster than they did before Delta arrived. Studies in a handful of other countries confirm that Delta causes more severe disease in younger people. For example, a study in Scotland reported that patients infected with Delta ran twice the risk of needing hospitalization. Researchers in Canada confirmed this and reported that young people infected with Delta had a 4-fold increased risk of requiring ICU care and double the risk of death. Other studies out of Singapore and India further corroborated these observations.

The emergence and rise of a viral variant with enhanced infectability and increased morbidity in younger, healthier patients is a prediction I and others have made in the face of the continuing global spread of this virus.

I told you so.

What does it all mean? Breakthrough infections we are now seeing in vaccinated people could be especially worrisome. The immunity conferred by vaccination usually retards viral spread and reduced viral replication scales down the development of new, more virulent viral variants. But, when immunized people do get infected and the virus grows in their bodies, the virus has to fight the vaccine immunity to eventually develop new mutations that allow the virus to simply brush off vaccine immunity. With Delta, we might be seeing the early stage of this viral evolution in vaxed people.

Vaccine resistance by the virus can be prevented by a rapid and robust vaccination effort as a team of European scientists recently reported in the journal Nature. It is imperative to get vaccines to countries that remain largely unvaccinated, and we need to get the naysayers in countries with more robust vaccine efforts to understand how their actions perpetuate the pandemic and promote the development of dangerous variants. There is no rational reason for the vast majority of people to refuse vaccination. The ongoing pandemic is totally preventable.

Vaccines have eradicated small pox in the world and polio from most developed countries. Measles is now extremely rare in the US thanks to vaccines. Go to an old cemetery and count the number of headstones belonging to children who died before 1950, then compare that to the number of kids who died after 1950. That striking difference is a powerful testimony to the effectiveness of vaccines as preventive medicine.

It is always better to prevent than to treat!

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A Critical Federal Vaccine Mandate

In response to the viral pandemic, the military ordered all service personnel to receive a controversial vaccine against the virus. The edict also prohibits military families and other civilians who live in high virus transmission areas from entering military bases. Furthermore, military personnel suspected of having contact with infected people are ordered to quarantine. All this was met with stiff opposition from many troops, from certain States, and even from Congress.

COVID-19 in 2021? 

No. Smallpox in 1777.

In 1777 facing an outbreak of smallpox that threatened his troops’ combat readiness, General George Washington ordered that all troops in the Continental Army be inoculated against smallpox. At the time, vaccination against smallpox was quite rare and not widely known. It involved a procedure known as variolation, where a small amount of pus from an active smallpox blister was scratched into the arm of a recipient. The low dose of the smallpox “pathogen” (the world did not know about viruses at that time) would, hopefully, just make the person sick and not kill him while conferring resistance to future smallpox exposure. Variolation was quite controversial and was even prohibited in Washington’s home state, Virginia. Variolation, in fact, did kill a relative of the King George of England. The relative was given too high a dose of pus and developed a full blown case of lethal smallpox. Many others also died from the procedure, hence the controversy.

When the revolution began, the Continentals faced not only the British military, but also the highly contagious smallpox virus carried by European troops coming from England and Germany. Europeans were well exposed to the disease where many survived and had protective immunity. Smallpox was relatively unknown in the Colonies so the colonists did not have that level of protection, and part of Washington’s genius was to realize that. As European troops arrived in Boston and New York, the virus spread through those cities and as the troops deployed, the disease threatened to run rampant through the colonies, potentially decimating the country and the Continental Army.

Washington, who survived smallpox as a child, was somewhat familiar with the rare practice of variolation, which was brought to England from Constantinople in 1721 by Lady Mary Wortley Montagu. By ordering it for his troops, despite stiff opposition from the Continental Congress, he acted as perhaps the country’s first public health advocate and averted a potentially disastrous epidemic among his troops.

After the battles of Lexington and Concord, the Continental Army encamped across the Charles River from Boston, which was stricken with smallpox from the arriving British soldiers. Washington prohibited anyone from Boston from entering his camps. He also swiftly quarantined anyone suspected of being infected, which was perhaps the first example of contact tracing. Washington’s actions were very heady stuff for the pre-epidemiology, pre-infectious disease era.

Washington did not immediately order variolation since he knew that the significant side effects of the procedure would temporarily incapacitate the troops who would take a few weeks to recover. Instead, he waited until the fighting subsided and both sides took a breather. Then he ordered the vaccinations against the wishes of the Continental Congress which initially forbade army surgeons from performing variolation.  Washington first ordered that all new recruits undergo the procedure believing that they would be healthy by the time they were battle ready and when the war was battle was ready for them.

Washington’s prescience was soon proven. Several thousand Continental troops marched on Quebec under Major General John Thomas who refused to follow Washington’s vaccination orders. He, and one-third of his 10,000 soldiers died from the pox and the force was soundly defeated.

Washington then moved to inoculate his main army and by 1777, 40,000 soldiers had been vaccinated in defiance of Congress. Infection rates in the Continental Army dropped from 20% to 1% and, after seeing these results, lawmakers soon repealed bans on variolation across the Colonies. One historian claims that Washington’s decision to inoculate his troops “…was the most important strategic decision of his military career.”

That radical decision could be a big reason why we do not today have the Union Jack flying over these 50 colonies. I find all of this to be an amazing, but little known fact about the American Revolution. Variolation might have been as important to the Colonists’ victory as was the French Navy finally showing up at Yorktown.

Immunology rocks as much as French naval cannons!

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