Thursday, January 3, 2013

Flu Shots: Clearing the Air, Correcting the citations/ Vancouver Sun

British Columbia 's chief medical officer pushed mandatory flu shots for healthcare workers, then backed up the policy with specious claims, showing he had not a clue what the science really said.  The Cochrane Collaboration's Tom Jefferson, MD, a flu vaccine expert who had reviewed the world literature and coauthored several Cochrane meta-analyses on the usefulness of the vaccine, brought him to task.  Too good to excerpt, here it is in full:
Dr. Perry Kendall’s responses to my comments (in Monday’s Vancouver Sun) are as disturbing as his original misreporting of my research. He states that the influenza vaccine is “60 per cent effective” and concludes that it reduces the chances somebody will pick up the virus and pass it on to patients. The figure of 60 per cent is a relative estimate which gives an inflated impression of performance. The best evidence of the performance of the influenza vaccine comes from trials in healthy adults. The relevant Cochrane review was first published in 1999 and has been updated several times since. The review shows that you need to vaccinate between 33 and 99 adults to avoid the onset of symptoms in one person. On average the vaccines prevent the loss of half a working day. There is no evidence in any literature that the vaccine avoids person-to-person spread as (chief health officer for B.C.) Kendall seems to imply. Another of his statements shows just how ideologically-driven his policies are. “When asked how many patients die each year because they pick up viruses like the flu, Kendall said he didn’t know because the information is not routinely collected.” If he does not know how many people die because of influenza, how does he know it’s a problem of such proportion to justify coercive policies? Also, how will he evaluate his policy which has caused so much resistance? If he does not know what the “before” looks like, how is he going to compare it with any “after” to assess whether Canadian taxpayers’ cash is well spent?
Perhaps the most bizarre of the statements made is that The Lancet, the British Medical Journal, the Canadian Medical Association Journal, the Society for Healthcare Epidemiology in the United States, they’ve all called for mandatory immunization of health care workers. Could Kendall please give us references to the BMJ and Lancet endorsement of mandatory immunization with influenza vaccines? The Canadian Medical Association Journal recently published an editorial with a misquote of our Cochrane review which was as distorted as Kendall’s.
The points made by Dr. Paul van Buynder and colleagues are equally vague. Van Buynder and colleagues state that the Cochrane Collaboration has a “narrow evidentiary standard.” Had they bothered to read our reviews they would have discovered that all relevant studies comparing vaccination of children, adults, elderly and health care workers with no vaccination have been included.
The problem is not inclusion, it’s the quality of what is included, as I have already explained. The are many studies in literature that conclude that vaccination of health care workers and healthy adults works well, but bias in these studies is so great that the vaccines appear to work against death for all causes, but not against death from respiratory infections.
Following this perverted logic would have inactivated vaccines save lives from accidents, strokes, accidental poisoning, hypothermia and falls, but not from influenza and pneumonia? Either the inactivated vaccines are miracle workers or there is something very wrong with the evidence. Cochrane reviews weigh the evidence by its quality, not by their conclusions, to allow interpretation of the study results with some confidence — this has nothing to do with “good” or “perfect.”
The statement that “the logic is indisputable” reveals a high degree of dogmatism. The inactivated vaccines should work in theory, just like many things work in theory, but real evidence suggests they are not having the desired effect. So far we have distortion of research findings, evidence-free statements and evidence-free policies supporting coercion of human beings. What next?
Dr. Tom Jefferson is with the Cochrane Respiratory Infections Group in Rome, Italy. 

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