H1N1 protection added to next season's flu shots
■ A CDC advisory panel recommends nearly everyone in the U.S. receive the new enhanced vaccine.
At the peak of the influenza A(H1N1) virus epidemic last year, Atlanta internist Sandra Fryhofer, MD, had to refuse vaccine for some patients because they did not fall into the priority groups set by the Centers for Disease Control and Prevention.
That shouldn't be a problem during the next flu season, as the Food and Drug Administration has decided to include a pandemic 2009 H1N1 virus in the Northern Hemisphere's 2010-11 seasonal influenza vaccine.
"This will make vaccine strategies much simpler so we can focus on getting people vaccinated and protected rather than trying to figure out which group they're in or should they get [the vaccine] now or later," said Dr. Fryhofer, clinical associate professor of medicine at Emory University School of Medicine and a member of the American Medical Association Council on Science and Public Health.
The FDA announced Feb. 23 that an A/California/7/2009 (H1N1)-like virus would be included in next season's flu vaccine. This is the same virus used in the 2009 H1N1 monovalent vaccine.
Also included in the upcoming influenza vaccine will be an A/Perth/16/2009 (H3N2)-like virus and a B/Brisbane/60/2008-like virus.
The FDA's move was followed a day later by a federal panel's recommendation to administer next season's flu vaccine to nearly all Americans, including healthy young people, a group that was disproportionately affected by H1N1.
The Advisory Committee on Immunization Practices, which advises the CDC on vaccine issues, on Feb. 24 voted to expand seasonal flu immunization to everyone except babies younger than 6 months.
Previous vaccine recommendations applied to about 85% of the population, but did not include healthy people age 19 to 49 unless they had close contact with others considered at high risk for the flu, according to the CDC.
ACIP's proposal will go to the CDC and Dept. of Health and Human Services. If approved, it would become policy and be considered the standard practice of care for vaccines, said CDC spokesman Tom Skinner.
"The 2009 H1N1 pandemic showed us that elderly people aren't necessarily the only ones at high risk for serious consequences of influenza," Skinner said. "The committee thought the time was now to really recommend everyone get a flu vaccine."
But there is concern that the increased demand for seasonal flu vaccine, caused by expanding the recommendations, could leave practices waiting longer than usual for requested doses, said family physician Tamarah Duperval, MD, MPH. Mile Square Health Center in Chicago, where Dr. Duperval is the medical director, typically receives seasonal flu vaccine near the end of November.
Meanwhile, a new seasonal flu immunization, Sanofi Pasteur's Fluzone High-Dose, will be available for adults 65 and older. This vaccine is formulated so that each 0.5 mL dose contains 180 micrograms of influenza virus hemagglutinin, rather than the 45 micrograms contained in other currently licensed seasonal flu vaccines for adults.
The FDA approved the high-dose vaccine in December 2009. ACIP at its February meeting gave the go-ahead for use but stopped short of recommending it until efficacy studies are available, Skinner said.
Flu vaccine demand
Skinner said it's difficult to predict how expanding the seasonal flu vaccine recommendations will affect manufacturers that struggled to meet high demand for H1N1 immunizations last year. Historically, fewer than half the number of people who are advised to get seasonal flu vaccine actually do, according to the CDC.
During the 2009-2010 flu season, about 114 million doses of seasonal vaccine were distributed, and nearly all of them were used, Skinner said. The CDC does not yet know how many of the vaccine recipients were in the recommended priority groups. But manufacturers base the number of seasonal vaccines they produce largely on the prior year's demand.
Interest in the H1N1 vaccine has dwindled since the U.S. epidemic peaked in late October 2009. But the CDC reported about 70 million doses of H1N1 vaccine had been administered as of Feb. 5.
No states reported widespread activity during the six weeks ending Feb. 20, according to the CDC. This contrasts with the end of October 2009, when H1N1 was widespread in 48 states.
CDC officials, however, emphasize that the virus is still circulating and that continued vaccination of the public is critical to prevent another wave of flu outbreaks.
Internationally, a committee of experts advised the World Health Organization on Feb. 23 that the pandemic has not yet peaked, noting that the Southern Hemisphere is preparing for winter, when influenza activity typically increases.