ACIP Endorses Universal Flu Vaccination
By Amesh A. Adalja, MD, March 3, 2010
On February 24, 2010, in response to novel risk factors that were elucidated during the 2009 H1N1 influenza pandemic, the U.S. Advisory Committee on Immunization Practices (ACIP) voted unanimously to recommend that the entire U.S. population receive annual influenza vaccination. The only exception is children under 6 months of age. A similar vote failed just 4 years ago. The text of the recommendations has not yet been released, but will be published in Morbidity and Mortality Weekly Report (MMWR).
Vaccine Target Groups Expanded Prior to ACIP Vote
In the U.S., in years past, influenza vaccination has been used to protect those at highest risk of serious complications—the very old and the very young. Prior to ACIP’s recent vote, recommendations had expanded to the extent that approximately 85% of the U.S. population met the criteria for influenza vaccination. During the 2009 pandemic, young adults, members of specific minority groups, and the obese were noted to be at particular risk for complications from influenza—factors that influenced the ACIP’s decision.
Infants Exempt from Recommendation
Children less than 6 months of age are exempted from the recommendation. In that age group, standard influenza vaccines exhibit poor immunogenicity because of immature immune systems and residual maternally-derived antibodies. The best protection for children of that age is herd immunity acquired through vaccination of contacts and maternal vaccination during pregnancy.
Increased Coverage Will Be Beneficial
In 2009, only 27.9% of the targeted population was vaccinated against H1N1 influenza, which is in line with the experience of the past few years, during which only about one-third of those targeted received seasonal flu vaccines.
While the call for universal vaccination will not result in 100% compliance, increased coverage of the population can be expected to have several important benefits. It should stem the spread of influenza, decrease the severity of illness that may break through, and increase market demand for seasonal influenza vaccines, which is an essential component of building capacity to ramp up production against pandemic strains that may occur in the future.
- ACIP recommends annual flu shots for almost all. CIDRAP News. February 24, 2010. http://www.cidrap.umn.edu/cidrap/content/influenza/swineflu/news/feb2410acip.html. Accessed March 1, 2010.
- Advisory Committee on Immunization Practices. http://www.cdc.gov/vaccines/recs/acip/. Accessed March 1, 2010.