April 15, 2015
Influenza Vaccinations Saved 40,000 Lives Over
a 9-Year Period

Atlanta—With more than 18% of flu vaccines received at drug stores or similar locations, pharmacists can take part of the credit for saving more than 40,000 lives over a 9-year period ending last year.

A new study, published online recently by the journal Vaccine, reports that influenza vaccination reduced deaths 22% compared to no immunization from the 2005-2006 flu season through 2013-2014. Seasonal flu-associated deaths in the U.S. range between 3,000 and 49,000 people each year, according to the CDC.

The study by CDC researchers indicates that most of the flu-associated deaths prevented, nearly 89%, were among Americans 65 or older. The next greatest beneficiaries were young children, 6 months through 4 years old.

The authors note that children younger than 5 and adults 65 and older are at high risk of serious flu complications and generally account for the vast majority of flu-associated deaths. Older Americans also have the highest flu-associated hospitalization rates; this season’s hospitalization rate among older flu patients is the highest percentage since that statistic has been tracked.

The most deaths were prevented during the 2012-2013 season, when nearly 9,400 deaths were averted by vaccination, despite modest estimated vaccine effectiveness that season, according to the report. Similar to the current 2014-2015 flu season, the most common circulating viruses then were H3N2 viruses.

The fewest deaths prevented by flu vaccination, however, occurred during the 2009 pandemic. Only 222 deaths were prevented by vaccination that season, according to study authors who explained that the 2009 monovalent pandemic vaccine did not become widely available until well after the peak of influenza illness had occurred. During the pandemic, flu activity was dominated by 2009 H1N1 virus circulation, with almost no seasonal viruses being detected.

To conduct the study, researchers applied statistical modeling to U.S. age group–specific estimates of flu-associated excess deaths, monthly flu vaccination coverage estimates, and summary seasonal flu vaccine effectiveness estimates.

“We estimated that a substantial number and proportion of influenza-related deaths were averted by recent U.S. influenza vaccination campaigns, even when indirect benefits of vaccination were not considered,” the authors conclude. “Our findings support annual influenza vaccination in the United States and suggest that both increased vaccination coverage and increased vaccine effectiveness would result in even more deaths averted.”

U.S. Pharmacist Social Connect