Public health officials recently announced they will make available a new influenza vaccine designed to battle the strain of the virus that caused the most illnesses during last year’s flu season this fall. The move, however, is not likely to quiet skeptics who have raised doubts about the efficacy — and safety — of the vaccine.
As Karen Kaplan reports in the Los Angeles Times, the Centers for Disease Control (CDC) has stockpiled nearly 180 million doses of vaccines that officials say will protect against the most common varieties of the virus, including the A/Switzerland strain, which was not detected before last year’s version of the vaccine was released.
Officials admit that “it is not possible” to accurately predict which strains of the flu will be most prevalent this fall. During a nationwide survey of flu cases conducted between May 24 and September 5, CDC researchers discovered three influenza strains never before seen in humans. Despite the uncertainty about the strains that may arise in the weeks ahead, they maintain (as they do every year) that vaccination remains “the best method for preventing influenza and its potentially severe complications.” But doubts about the vaccine’s effectiveness persist.
According to the CDC’s own data, those who were vaccinated during last year’s flu season were only 23 percent less likely than those who declined the shot to end up in a doctor’s office with flulike symptoms. They blame this performance on the late arrival of the A/Switzerland strain, but other studies have shown the vaccines to be perennially ineffective.
A 2014 review of 90 studies published by the Cochrane Collaborative, a Canada-based network of healthcare researchers, found that “vaccination shows no appreciable effect on working days lost or hospitalization.”
Epidemiologist Tom Jefferson, MD, who contributed to a similar Cochrane report in 2009, said in this EL piece: “Public health interventions such as hygiene measures and barriers to interrupt or reduce the spread of respiratory viruses have a much better evidence base than vaccines. They are also cheaper, yet they are almost ignored.”
The most recent Cochrane study disputed claims about the vaccine’s safety, but the widespread use of thimerosal as a preservative in multidose vials of the vaccine continues to raise concerns. A heavy-metal mercury, thimerosal has been linked to neurological and inflammatory diseases. Last year, the CDC came under intense criticism when an internal report was released showing that officials there had been informed in 2000 that thimerosal exposure from the vaccine posed a “very high risk” for autism and other neurological disorders.
The agency, and the vast majority of public health organizations, continue to claim the vaccines are safe — and more effective against the flu than avoiding the seasonal shot altogether. To decide for yourself, see “The Debate About Flu Shots” in our October 2012 issue.