Does the Vaccine Matter?

Tuesday, October 27th, 2009

Shannon Brownlee and Jeanne Lenzer ask, Does the vaccine matter? They’re referring to the flu vaccine, and they make a number of interesting points:

  • The elderly account for 90 percent of deaths from seasonal flu.
  • Unfortunately, the elderly, particularly those over age70, don’t have a good immune response to vaccine.
  • At most half, and perhaps as few as 7 or 8 percent, of “flu” cases are actually caused by an influenza virus in any given year. More than 200 known viruses and other pathogens can cause “influenza-like illness” — respiratory syncytial virus, bocavirus, coronavirus, and rhinovirus, etc. — and, in up to two-thirds of the cases of flu-like illness, no cause at all can be found.
  • Every year, the World Health Organization and the Centers for Disease Control and Prevention collect data from 94 nations on the flu viruses that circulated the previous year, and then make an educated guess about which viruses are likely to circulate in the coming fall. Based on that information, the U.S. Food and Drug Administration issues orders to manufacturers in February for a vaccine that includes the three most likely strains.
  • Most reports coming from the Southern Hemisphere in late August (the end of winter there) suggested that the swine flu is highly infectious, but not particularly lethal. For example, Australian officials estimated they would finish winter with under 1,000 swine flu deaths—fewer than the usual 1,500 to 3,000 from seasonal flu. Among those who have died in the U.S., about 70 percent were already suffering from congenital conditions like cerebral palsy or underlying illnesses such as cancer, asthma, or AIDS, which make people more vulnerable.
  • Study after study has found that people who get a flu shot in the fall are about half as likely to die that winter — from any cause — as people who do not.
  • When researchers from the National Institute of Allergy and Infectious Diseases included all deaths from illnesses that flu aggravates, like lung disease or chronic heart failure, they found that flu accounts for, at most, 10 percent of winter deaths among the elderly.
  • Tom Jefferson, a physician based in Rome and the head of the Vaccines Field at the Cochrane Collaboration, a highly respected international network of researchers who appraise medical evidence, says: “For a vaccine to reduce mortality by 50 percent and up to 90 percent in some studies means it has to prevent deaths not just from influenza, but also from falls, fires, heart disease, strokes, and car accidents. That’s not a vaccine, that’s a miracle.”
  • Jackson’s findings showed that outside of flu season, the baseline risk of death among people who did not get vaccinated was approximately 60 percent higher than among those who did, lending support to the hypothesis that on average, healthy people chose to get the vaccine, while the “frail elderly” didn’t or couldn’t. In fact, the healthy-user effect explained the entire benefit that other researchers were attributing to flu vaccine, suggesting that the vaccine itself might not reduce mortality at all.
  • In 2004, for example, vaccine production fell behind, causing a 40 percent drop in immunization rates. Yet mortality did not rise. In addition, vaccine “mismatches” occurred in 1968 and 1997: in both years, the vaccine that had been produced in the summer protected against one set of viruses, but come winter, a different set was circulating. In effect, nobody was vaccinated. Yet death rates from all causes, including flu and the various illnesses it can exacerbate, did not budge.
  • Majumdar, a physician and researcher at the University of Alberta, in Canada, offers another historical observation: rising rates of vaccination of the elderly over the past two decades have not coincided with a lower overall mortality rate. In 1989, only 15 percent of people over age 65 in the U.S. and Canada were vaccinated against flu. Today, more than 65 percent are immunized. Yet death rates among the elderly during flu season have increased rather than decreased.
  • The federal government has spent $3 billion stockpiling millions of doses of antiviral drugs like Tamiflu.
    Flu can become resistant to Tamiflu in a matter of days.

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