Influenza Vaccination
How much damage has been done over the years, during this seemingly useless campaign? How much money has been made? Why is the advice still to have the influenza vaccine?
Taken from:
http://www.pir-interims.com/news_menu/detail.html?news_id=57
Influenza vaccine benefits exaggerated in elderly
Pharmatimes – 26 September 2007
The benefits of vaccinating the elderly against influenza have been greatly exaggerated, according to a major review of the literature published in the latest issue of The Lancet Infectious Diseases. Health policy in most Western countries aims to cuts flu deaths by targeting people aged at least 65 years for vaccination. However, the authors from George Washington University, Washington DC, point out that although placebo-controlled randomised trials show the influenza vaccine is effective in younger adults, few trials have included elderly people, and especially those aged at least 70 years. This age group is supposed to account for three-quarters of all influenza-related deaths. They add that recent excess mortality studies have been unable to confirm a decline in influenza-related mortality since 1980, even though vaccination coverage increased from 15% to 65% during this period.
Other source: www.thelancet.com
All this is not new. This item appeared on the BMJ website in October 2006:
http://www.bmj.com/cgi/content/full/333/7574/912
Summary Points:
1. Public policy worldwide recommends the use of inactivated influenza vaccines to prevent seasonal outbreaks
2. Because viral circulation and antigenic match vary each year and non-randomised studies predominate, systematic reviews of large datasets from several decades provide the best information on vaccine performance
3. Evidence from systematic reviews shows that inactivated vaccines have little or no effect on the effects measured
4. Most studies are of poor methodological quality and the impact of confounders is high
5. Little comparative evidence exists on the safety of these vaccines
6. Reasons for the current gap between policy and evidence are unclear, but given the huge resources involved, a re-evaluation should be urgently undertaken.
The optimistic and confident tone of some predictions of viral circulation and of the impact of inactivated vaccines, which are at odds with the evidence, is striking. The reasons are probably complex and may involve "a messy blend of truth conflicts and conflicts of interest making it difficult to separate factual disputes from value disputes"22 or a manifestation of optimism bias (an unwarranted belief in the efficacy of interventions).23