Flu Vaccine Curbs Hospitalization in the Elderly

March 13, 2013

By David Douglas

NEW YORK (Reuters Health) Mar 13 - Vaccination can avert well over half of all influenza-associated hospitalizations, according to an effectiveness study by Tennessee-based researchers.

In fact, Dr. Marie R. Griffin told Reuters Health by email, "We estimated that the influenza vaccine prevented 70% of influenza-associated hospitalizations due to pneumonia and other acute respiratory hospitalizations in older adults during the 2011-2012 influenza season."

Dr. Griffin and colleagues at Vanderbilt University Medical Center, Nashville studied adults hospitalized with respiratory symptoms at one academic and three community hospitals during the influenza season. Among those excluded were patients with symptoms for greater than 10 days and those who had been treated with antivirals. The findings were published online February 28th in Clinical Infectious Diseases.

Of 169 patients with vaccine status verified, 17 (10%) had confirmed influenza. Of the 104 vaccinated patients, 6% were positive for influenza compared to 17% of the 65 patients who were not vaccinated.

After adjustment, vaccine effectiveness across all age groups for preventing influenza-associated hospitalizations was 71.4%. For those aged 50 years or more, it was 76.8%.

When a further 28 participants who only had self-reported vaccination were included, the effectiveness was 69.9%. Propensity score models yielded similar results.

"This estimate was similar to the 60% effectiveness we reported for three previous years," Dr. Griffin added.

"This study," she concluded, "should encourage more older adults to get the influenza vaccine every year."

SOURCE: http://bit.ly/WHETUG

Clin Infect Dis 2013.