02 July 2009
Scientists Take Lessons from Past Pandemics for New H1N1 Virus
U.S. provides anti-virals to Latin America, Caribbean to fight pandemic flu
Washington — As cases of the novel H1N1 flu rise to 77,201 worldwide and three new human cases of highly pathogenic H5N1 avian flu bring that global total to 436 since 2003, scientists in the United States are examining past pandemics for lessons that might help with the response to the 2009 pandemic H1N1.
Deaths from the novel H1N1 flu stand at 332 in 16 of 115 countries officially reporting cases to the World Health Organization (WHO). Deaths from H5N1 — the majority in Indonesia (141) and Vietnam (111) — total 262 in 11 of 15 countries that have reported H5N1 cases to WHO.
To help with the spreading and moderately severe wave of illness, U.S. Health and Human Services Secretary Kathleen Sebelius announced July 2 that the United States will provide 420,000 treatment courses of the anti-viral medication Tamiflu (oseltamivir) to the Pan American Health Organization to help fight the pandemic in Latin America and the Caribbean.
“The U.S. is committed to supporting and enhancing the health security in the region by reducing transmission and severity of illness,” Sebelius told officials at a meeting for health ministers throughout the Americas in Cancun, Mexico.
Pharmaceutical companies also are making contributions. On June 17 at the Pacific Health Summit in Seattle, Christopher Viehbacher, chief executive of Sanofi-Aventis, announced that his company would donate 100 million doses of an H1N1 vaccine to WHO to help developing countries fight the pandemic.
On July 1, Tamiflu maker Roche announced a program to produce and store Tamiflu stockpiles for developing countries that are members of the Global Alliance for Vaccines and Immunization at a significantly reduced price and spread the cost over several years.
H1N1 HISTORY
Scientists around the world are working to understand the novel H1N1 virus and how it will ultimately play out among people planetwide. The search for knowledge includes every available tool, from epidemiology, systems biology and molecular genetics to an examination of pandemics and outbreaks caused by other H1N1 viruses in the 20th century.
Different genetic strains of the H1N1 virus were involved in the deadly 1918–1919 pandemic, an epidemic in the United States in 1976 and a reemergence of the virus in 1977 in the former Soviet Union, Hong Kong and northeastern China.
Since 1977, Dr. Shanta Zimmer and Dr. Donald Burke wrote in the June 29 edition of the New England Journal of Medicine, human H1N1 strains derived from the 1918 H1N1 virus have circulated in people and have “maintained a continual presence during seasonal epidemics.”
“All human-adapted influenza A viruses of today — both seasonal variations and those that caused more dramatic pandemics,” Dr. Jeffery Taubenberger of the National Institute of Allergy and Infectious Diseases (NIAID) said in a June 29 statement, “are descendents, direct or indirect, of that founding [1918] virus.”
Taubenberger, Dr. David Morens and NIAID Director Dr. Anthony Fauci are coauthors of an article published online June 29 by the New England Journal of Medicine. They write that the world has been in an influenza pandemic era since 1918 and the 2009 H1N1 virus is part of that original viral family.
PANDEMIC LESSON
In 1918–1919, a deadly flu pandemic spread a human H1N1 virus worldwide and killed up to 50 million people. That virus, Zimmer and Burke wrote, “is thought to have emerged almost simultaneously from birds into humans and swine. In contrast, [the 2009 H1N1 virus] probably emerged from swine into humans.”
In January 1976, an outbreak of respiratory disease occurred among soldiers returning to an Army base in Fort Dix, New Jersey. A novel H1N1 swine-origin virus was identified as the cause of the epidemic that resulted in 230 cases and one death.
“When the CDC isolated this virus,” Dr. Harvey Fineberg, director of the Institute of Medicine, said in a June 30 briefing at the Center for Strategic and International Studies in Washington, “they called together their advisers and thought hard about what to do.”
The decision, made in March 1976 by the White House and a group of leading virologists that included polio-vaccine developers Albert Sabin and Jonas Salk, “was to mount a nationwide public-private immunization campaign to protect the American public against influenza,” Fineberg said.
By October 1976, he said, “with no transmission anywhere in the country [outside Fort Dix], the campaign was ready to go forward and in the first 10 days 1 million people were immunized.”
Ultimately, the program produced 40 million civilian vaccinations, Zimmer and Burke wrote, and 532 cases of the paralysis-causing Guillain-Barre syndrome, a rare side effect of that flu vaccination, before the vaccination campaign was halted in December 1976.
EXIT RAMPS
“As a policy matter,” Fineberg said, “rolling up every aspect of the decision into a single go-no go proposition way back in March [1976] was premature and probably unwise and certainly unnecessary because there was additional information to be learned in the coming months.”
At the same briefing, Fauci said CDC had isolated the novel H1N1 virus for vaccine production and distributed it to manufacturing companies that have made pilot lots of the vaccine. The National Institutes of Health will perform clinical trials to make sure the vaccines are safe, to determine dose amounts and to test the responses of special populations like pregnant women and the elderly.
“If everything goes right,” Fauci said, “we hope to start vaccinating people — if the decision is made to vaccinate people — throughout the fall and get as many people protected, especially those in high-risk groups, for the fall season,” when scientists expect a possible second wave of novel H1N1 infections.
“The decision to test, the decision to produce and the decision to administer are completely uncoupled,” he added. “This is different from 1976, where in one day, in one room, the decision was made to make and administer [a vaccine], with no exit ramps on that approach. Even though there were no new cases of swine flu throughout 1976, the train was out of the station. Right now, we have multiple steps along the way in which we can stop or go.”
