Given that concerns and myths about the safety of the seasonal flu vaccine have persisted for decades among members of the public and even health care workers, it is worth noting that an exhaustive influenza report concluded that “the currently licensed influenza vaccines in the United States are among the safest of all available vaccines.”
The report by the Center for Infectious Disease Research & Policy (CIDRAP) at the University of Minnesota in Minneapolis states that “while unique adverse events can occur with use of these vaccines, such events are extremely rare. Given the level of safety of the current influenza vaccines, it will be challenging for new influenza vaccines to match or exceed the current safety profile.”
Despite an excellent overall safety record, the seasonal influenza vaccine has been associated with several unique adverse events, CIDRAP reported. Foremost among these, of course, was the ‘swine flu’ incident in 1976, which began with an outbreak of a novel strain of H1N1 influenza among military recruits at Fort Dix, NJ. More than 200 cases, including 13 severe respiratory infections and one death were reported. Concerned that the novel strain could result in a pandemic, public health officals developed a strain-specific vaccine and a nationwide immunization effort began. During the campaign, public health officials noted an unusual increase in reports of Guillain-Barré syndrome (GBS) following influenza vaccination.
A relatively rare neurologic disorder, GBS was occurring in vaccine recipients about nine times higher than the expected background rate of less than one case per million vaccinated. This increased risk resulted in suspension of the immunization campaign, but “researchers still do not know why this particular vaccine caused an increased risk of GBS,” CIDRAP concluded.