The Atlanta Journal-Constitution
How good are flu shots?
Report finds vaccinations offer modest protection.
It’s flu-shot season, and public health officials are urging everyone over 6 months of age to get one. By 2020, U.S. health leaders want 80 percent of the population to get yearly shots.
For vaccine manufacturers, it’s a bonanza: Influenza shots — given every year, unlike many other vaccines — are a multibillion-dollar global business. But how good are they? Last month, in a step tantamount to heresy in the public health world, scientists at the Center for Infectious Disease Research and Policy at the University of Minnesota released a report saying influenza vaccinations provide only modest protection for healthy young and middle-age adults, and little if any protection for those 65 and older, who are most likely to succumb to the illness or its complications. Moreover, the report’s authors concluded, federal vaccination recommendations, which have expanded in recent years, are based on inadequate evidence and poorly executed studies.
While researching the report released last month, the authors discovered a recurring error in influenza vaccine studies that led to an exaggeration of the vaccine’s effectiveness, said CIDRP director Michael T. Osterholm, who also heads the Center of Excellence for Influenza Research and Surveillance. They also discovered 30 inaccuracies in the statement on influenza vaccines put forth by the expert panel that develops vaccine recommendations, all of which favor the vaccine.
Centers for Disease Control and Prevention officials acknowledge that the vaccines do not work as well in the elderly population as they do in younger healthy adults. But, they say, the effectiveness of the flu shots, which are reformulated every year in an attempt to match the strains most likely to be circulating that season, varies depending on the population being inoculated and the year.
“Does it work as well as the measles vaccine? No, and it’s not likely to. But the vaccine works,” said Dr. Joseph Bresee, chief of epidemiology and prevention in the CDC’s influenza division.
Although the vaccine may be less effective at preventing influenza in the elderly, Bresee said, that is the population most susceptible to the disease and at highest risk. Anywhere from as few as 3,000 to as many as 49,000 Americans die of influenza each year, some 90 percent of them elderly.
The CIDRP report is not the first to point out the shortcomings of influenza vaccines. The Cochrane Collaboration, an international network of experts that evaluates medical research, concluded in a 2010 review that the vaccines decrease symptoms in healthy adults under 65 and save people about a half-day of work on average, but that they do not affect the number of people hospitalized and have minimal impact in seasons when vaccines and viruses are mismatched.
It also concluded that the vaccines appear to have no effect on hospital admissions, transmission or rates of complications.
CDC officials say population-based studies show elderly people who get flu shots are less likely to die of any cause than elderly people who do not get them.