Researchers Believe Influenza Vaccines Need Improvement
SOURCE: Medscape Medical News
By Larry Hand
October 25, 2011 — Critical gaps exist in the evidence for the effectiveness of licensed influenza vaccines in the United States, researchers report in an article published online October 25 in The Lancet Infectious Diseases. Individuals who are at risk for medical complications or people who are aged 65 years or older are especially affected by the gaps, the researchers write.
The researchers conducted a meta-analysis of 31 studies that used laboratory tests to confirm influenza infections. These studies were selected from 5707 studies identified, published over a period of 40 years. The authors found that trivalent inactivated vaccine, which is used for 90% of influenza vaccinations in the United States, is only effective in preventing infection in 59% of healthy adults. They also found live attenuated influenza vaccine, which is not approved for adults who are aged 50 years or older, to be effective in 83% of children aged 7 years or younger, and in 69% of people younger than 65 years.
“The ongoing health burden caused by seasonal influenza and the potential global effect of a severe pandemic suggests an urgent need for a new generation of more highly effective and cross-protective vaccines that can be manufactured rapidly,” write Michael Osterholm, PhD, MPH, from the University of Minnesota, Minneapolis, and lead author of the study, and colleagues. “In the meantime, we should maintain public support for present vaccines that are the best intervention available for seasonal influenza.” (more…)