Adjuvanted flu vaccine more effective in older patients
Researchers with the Influence65 study group found the AS03 adjuvanted vaccine could improve efficacy rates among older adults, the Lancet Infectious Diseases reports.
"Although few vaccine efficacy and effectiveness studies have been done in elderly adults, the substantial burden of influenza in this population despite widespread vaccination suggests that vaccines with increased efficacy are needed," the researchers said, according to the Lancet Infectious Diseases.
The researchers conducted the randomized trial in 15 countries during the 2008-2009 and 2009-2010 influenza seasons. Patients at least 65 years of age received either the AS03 adjuvanted trivalent vaccine or a non-adjuvanted trivalent vaccine. Of the 43,802 participants, 21,893 were given the adjuvanted vaccine and 21,802 were given the non-adjuvanted vaccine.
The Influence65 study group found influenza A and influenza B were less common among the patients who received the AS03-adjuvanted vaccine with a relative efficacy of 12.11 percent. Fewer patients who received the adjuvanted vaccine were infected with influenza A, with a relative efficacy rate of 17.53 percent. The same was true with the vaccine and influenza A H3N2, with a relatively efficacy rate of 22 percent, the Lancet Infectious Diseases reports.
"Our study suggests that the benefit of influenza vaccination in elderly people might vary depending on influenza subtypes," the researchers said, according to the Lancet Infectious Diseases. "Although findings for our primary endpoint were not significant, our trial had 43,000 elderly participants in stable health and provides valuable lessons for assessment of new influenza vaccines in this population."