In a review of influenza vaccine studies, researchers found that the studies sponsored by industry are treated more favorably by medical journals -- even when the studies are of poor quality.

According to Barbara Loe Fisher, president of the National Vaccine Information Center (NVIC), this confirms that drug companies marketing vaccines have undue influence on what gets published in medical journals regarding vaccine safety and effectiveness.

The researchers identified and assessed more than 270 published studies on influenza vaccines, and found no relationship between study quality, publication in prestige journals or their subsequent citation in other articles. Instead, the single most important factor determining where the studies were published or how often they were cited was sponsorship, with those partially or wholly funded by the pharmaceutical industry having higher visibility.