Pandemrix, an adjuvanted influenza vaccine used in the U.K., but not the U.S. during the 2009 H1N1 pandemic, appears to have been associated with a consistently higher rate of adverse events compared to two other vaccines, an investigation found.
In addition to the highly reported narcolepsy, an analysis found that both rates of adverse events and serious adverse events were higher compared to another adjuvanted vaccine, Arepanrix, and an unadjuvanted H1N1 vaccine, reported assistant editor Peter Doshi, writing in The BMJ.
Doshi wrote that this data was obtained through the pretrial discovery process from prosecutors suing various Irish governmental agencies and the manufacturer, GlaxoSmithKline. It showed there was a “striking difference in the number and frequency of adverse events” in postmarketing safety reports. For example, Doshi’s colleague, Tom Jefferson, cites an odds ratio of 5.39 (95% CI 3.70-7.85) for deaths for Pandemrix compared to the other comparator vaccines.
In the BMJ‘s own analysis of the data, they found that Pandemrix had “proportionally, five times more adverse events reported” than the other two vaccines, including “four times the rate of facial palsy, eight times the rate of serious adverse events, nine times the rate of convulsions.”
“Clinicians were not provided, nor did they have access to, important information regarding the safety profile of pandemic influenza vaccines. Clinicians’ ability to help patients make informed decisions is impaired by a lack of transparency of full data on potential harms,” Doshi told MedPage Today. “The lesson here is that what happened is unacceptable, and we must demand greater transparency of information — whether that be for vaccines, drugs, or devices.”
In the article, Doshi noted that “neither GSK nor the health authorities seem to have made the information public — nor is it clear that the disparity was investigated,” in contrast to the widely reported findings on narcolepsy.
Amesh Adalja, MD, a spokesperson for the Infectious Diseases Society of America (IDSA) and senior scholar at Johns Hopkins Center for Health Security in Baltimore, told MedPage Today that this piece raises “important scientific questions,” but as the article itself points out, it is not enough to establish causation.
Adalja added that more side effects are to be expected with an adjuvanted vaccine.
“It’s going to stimulate the immune system more,” he said. “That’s the tradeoff of a vaccine in the face of a pandemic of unknown severity and unknown risk, we accept vaccines with more side effects and more risk.”
Doshi said that the manufacturer declined to answer several questions due to “ongoing litigation,” including “whether it ever undertook any investigations to understand the discrepancy in adverse event reporting between Pandemrix and Arepanrix, whether it notified healthcare providers about the discrepancies, whether it considered pulling Pandemrix from the market, or considered recommending Arepanrix or another company’s vaccine.”
“Without transparency of information, we cannot fully expect the public to trust in public health recommendations — whether they be for vaccines or statins or screening or something else,” Doshi told MedPage Today, adding that all the vaccines discussed were taken off the market years ago, and not seasonal influenza vaccines.
Adalja said that this does not apply to the current adjuvanted influenza vaccine used in the U.S. for elderly patients and this “should not dissuade practitioners from using it.”
Doshi disclosed being a colleague of Tom Jefferson, who was quoted in the original article.