MADISON, WI - A new, highly detailed study of the H1N1 flu virus shows that the pathogen is more virulent than previously thought.
Writing in a fast-tracked report published recently (July 13, 2009) in the journal Nature, an international team of researchers led by University of Wisconsin-Madison virologist Yoshihiro Kawaoka provides a detailed portrait of the pandemic virus and its pathogenic qualities.
In contrast with run-of-the-mill seasonal flu viruses, the H1N1virus exhibits an ability to infect cells deep in the lungs, where it can cause pneumonia and, in severe cases, death. Seasonal viruses typically infect only cells in the upper respiratory system.
"There is a misunderstanding about this virus," says Kawaoka, a professor of pathobiological sciences at the UW-Madison School of Veterinary Medicine and a leading authority on influenza. "People think this pathogen may be similar to seasonal influenza. This study shows that is not the case. There is clear evidence the virus is different than seasonal influenza."
The ability to infect the lungs, notes Kawaoka, is a quality frighteningly similar to those of other pandemic viruses, notably the 1918 virus, which killed tens of millions of people at the tail end of World War I. There are likely other similarities to the 1918 virus, says Kawaoka, as the study also showed that people born before 1918 harbor antibodies that protect against the new H1N1 virus.
And it is possible, he adds, that the virus could become even more pathogenic as the current pandemic runs its course and the virus evolves to acquire new features. It is now flu season in the world's southern hemisphere, and the virus is expected to return in force to the northern hemisphere during the fall and winter flu season.
To assess the pathogenic nature of the H1N1 virus, Kawaoka and his colleagues infected different groups of mice, ferrets and non-human primates - all widely accepted models for studies of influenza - with the pandemic virus and a seasonal flu virus. They found that the H1N1 virus replicates much more efficiently in the respiratory system than seasonal flu and causes severe lesions in the lungs similar to those caused by other more virulent types of pandemic flu.
"When we conducted the experiments in ferrets and monkeys, the seasonal virus did not replicate in the lungs," Kawaoka explains. "The H1N1 virus replicates significantly better in the lungs."
The new study was conducted with samples of the virus obtained from patients in California, Wisconsin, the Netherlands and Japan.
The new Nature report also assessed the immune response of different groups to the new virus. The most intriguing finding, according to Kawaoka, is that those people exposed to the 1918 virus, all of whom are now in advanced old age, have antibodies that neutralize the H1N1 virus. "The people who have high antibody titers are the people born before 1918," he notes.
Kawaoka says that while finding the H1N1 virus to be a more serious pathogen than previously reported is worrisome, the new study also indicates that existing and experimental antiviral drugs can form an effective first line of defense against the virus and slow its spread.
There are currently three approved antiviral compounds, according to Kawaoka, whose team tested the efficacy of two of those compounds and the two experimental antiviral drugs in mice. "The existing and experimental drugs work well in animal models, suggesting they will work in humans," Kawaoka says.
Antiviral drugs are viewed as a first line of defense, as the development and production of mass quantities of vaccines take months at best.
In addition to his appointment at UW-Madison, Kawaoka also is a professor at the University of Tokyo. The new study was funded by grants from the U.S. National Institutes of Health, and the Japanese Ministry of Education, Culture, Sports, Science and Technology.
Caption: The pandemic H1N1 flu virus (red) has been shown to be more virulent than scientists previously believed. The filamentous shape of the virus, which in this image have recently budded from infected cells, is also unusual.
© 2009 Steven S. Clark, PhD, some rights reserved. Articles contained herein, are meant to be distributed freely to interested parties. However, any use, including excerpts from any article, must credit Steven S. Clark and provide a link to the original article published in BioScience Biz.
Disclaimer: The authors used their best efforts in collecting and preparing the information published herein. However, neither Steven S. Clark, nor other authors, assume, and hereby disclaim, any and all liability for any loss or damage caused by errors or omissions, whether such errors or omissions resulted from negligence, accident, or other causes.
The SBIR Clock is Ticking
Members of the Senate Small Business and Entrepreneurship Committee and the House Small Business, and Science and Technology Committees are meeting, yet again, to see if this time they can resolve the impasse of two very different SBIR reauthorization bills, (Senate S.1233 and House H.R.2965).
You will recall that Rep. Nydia Velazquez (D-NY), chairwoman of the House Small Business Committee, holds the very anti-small business view that VC-owned technology companies should be able to participate fully in SBIR/STTR competition. Amazingly, she has for the last two years, prohibited any testimony on behalf of small businesses in her committee and also on the floor of the House. In contrast, the Senate’s bill preserves most of the SBIR program for small company by capping participation of VC’s, a compromise that last year was agreeable to both the VC and small business lobbies. But the Velazquez would not budge from her position.
Will this year be different?
When the full House considered its SBIR reauthorization bill, Velazquez got the Rules Committee to prohibit consideration of a Edward Markey (D-MA)-led amendment that would have made the bill similar to the Senate version. She did this because it was widely expected that the Markey amendment was favored by most members of the House and would have passed.
Several House members, led by Markey, who disagree with the obstructionist Velazquez and do not like her bullying, are trying an end run around her by sending a letter to Senator Mary Landrieu (D-LA), Chair of the Senate Small Business and Entrepreneurship Committee, expressing their support for the Senate’s SBIR reauthorization bill. This letter represents an attempt to let the Senate conference committee members know that most Representatives disagree with Velazquez’s bill.
The more members of the House who sign the letter, the greater chance that the conference committee will approve S.1233 as the final version. You can help by emailing the Markey letter to your Representative and ask that s/he sign on this week. Time is of the essence since an acceptable compromise must be made by next Tuesday, July 28. While you are at it, ask your Rep to consider how they are going to explain to small businesses in their state why they voted against small businesses so that rich VC’s could have access to more Federal funds.
SBIR updates and links for contacting your Representatives and Senators can be found on www.SBIRreauthorization.com.
© 2009 Steven S. Clark, PhD, some rights reserved. Articles contained herein, are meant to be distributed freely to interested parties. However, any use, including excerpts from any article, must credit Steven S. Clark and provide a link to the original article published in BioScience Biz.
Disclaimer: The authors used their best efforts in collecting and preparing the information published herein. However, neither Steven S. Clark, nor other authors, assume, and hereby disclaim, any and all liability for any loss or damage caused by errors or omissions, whether such errors or omissions resulted from negligence, accident, or other causes.