The negative finding of a comprehensive review of 50 published reports by the
highly credible Cochrane Collaboration should discourage healthy people
from getting a flu shot.
This is the season that many Americans are advised-even pressured--to
get flu shots. Indeed, flu shots are being hawked at every drug store
chain...
But what does the evidence show about the effectiveness of the flu
vaccine when vaccinated and unvaccinated groups are compared ?
Well, the finding of a comprehensive review of 50 published reports by the highly credible Cochrane Collaboration should discourage healthy people from getting the flu shot:
"The results of this review seem to discourage the utilisation of
vaccination against influenza in healthy adults as a routine public
health measure.
As healthy adults have a low risk of complications due
to respiratory disease, the use of the vaccine may be only advised as an
individual protection measure against symptoms in specific cases."
Specifically, the EVIDENCE REFUTES the claims that the flu vaccine
prevents the flu;
the EVIDENCE REFUTES the claim that it prevents viral
transmission in healthy adults;
and the EVIDENCE REFUTES the claim that the
vaccine prevents complications and "saves lives."
The EVIDENCE shows little or no benefit for influenza vaccinations.
"This review includes 15 out of 36 trials funded by
industry (four had no funding declaration). An earlier systematic review
of 274 influenza vaccine studies published up to 2007 found industry
funded studies were published in more prestigious journals and cited
more than other studies independently from methodological quality and
size. Studies funded from public sources were significantly less likely
to report conclusions favorable to the vaccines. The review showed that
reliable evidence on influenza vaccines is thin but there is evidence of
widespread manipulation of conclusions and spurious notoriety of the
studies. The content and conclusions of this review should be
interpreted in light of this finding."
Repeat:
“…industry funded studies were published in more prestigious journals and cited more than other studies…”
“…reliable evidence on influenza vaccines is thin…”
“…there is evidence of widespread manipulation of conclusions…”
Most assuredly, the “content and conclusions of this review should be interpreted in light of this finding”!
So, it would be prudent to be highly skeptical about the
pronouncements and recommendations of public health officials about the
value or necessity of various vaccines.
There are hidden financial conflicts of interest.
See, Part III of AHRP's examination of America's Healthcare Crisis http://www.ahrp.org/cms/content/view/873/9/
with links to a detailed analysis of the intricate web of financial
conflicts of interest that dominate public health vaccine policies.
Vera Sharav
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
See: http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD001269.pub4/abstract
The Cochrane Collaboration (Wiley publication)
Vaccines for preventing Influenza in Healthy Adults
Tom Jefferson, Carlo Di Pietrantonj ,Alessandro Rivetti ,Ghada A Bawazeer ,Lubna A Al-Ansary ,Eliana Ferroni
Published Online: 7 JUL 2010
We included 50 reports. Forty (59 sub-studies) were clinical trials of
over 70,000 people. Eight were comparative non-RCTs and assessed serious
harms. Two were reports of harms which could not be introduced in the
data analysis. In the relatively uncommon circumstance of vaccine
matching the viral circulating strain and high circulation, 4% of
unvaccinated people versus 1% of vaccinated people developed influenza
symptoms (risk difference (RD) 3%, 95% confidence interval (CI) 2% to
5%). The corresponding figures for poor vaccine matching were 2% and 1%
(RD 1, 95% CI 0% to 3%). These differences were not likely to be due to
chance. Vaccination had a modest effect on time off work and had no
effect on hospital admissions or complication rates. Inactivated
vaccines caused local harms and an estimated 1.6 additional cases of
Guillain-Barré Syndrome per million vaccinations. The harms evidence
base is limited.
Authors' conclusions
Influenza
vaccines have a modest effect in reducing influenza symptoms and
working days lost. There is no evidence that they affect complications,
such as pneumonia, or transmission.
WARNING:
This
review includes 15 out of 36 trials funded by industry (four had no
funding declaration). An earlier systematic review of 274 influenza
vaccine studies published up to 2007 found industry funded studies were
published in more prestigious journals and cited more than other studies
independently from methodological quality and size. Studies funded from
public sources were significantly less likely to report conclusions
favorable to the vaccines. The review showed that reliable evidence on
influenza vaccines is thin but there is evidence of widespread
manipulation of conclusions and spurious notoriety of the studies. The
content and conclusions of this review should be interpreted in light of
this finding.
Plain language summary
Over
200 viruses cause influenza and influenza-like illness which produce
the same symptoms (fever, headache, aches and pains, cough and runny
noses). Without laboratory tests, doctors cannot tell the two illnesses
apart. Both last for days and rarely lead to death or serious illness.
At best, vaccines might be effective against only influenza A and B,
which represent about 10% of all circulating viruses. Each year, the
World Health Organization recommends which viral strains should be
included in vaccinations for the forthcoming season.
Authors of
this review assessed all trials that compared vaccinated people with
unvaccinated people. The combined results of these trials showed that
under ideal conditions (vaccine completely matching circulating viral
configuration) 33 healthy adults need to be vaccinated to avoid one set
of influenza symptoms. In average conditions (partially matching
vaccine) 100 people need to be vaccinated to avoid one set of influenza
symptoms. Vaccine use did not affect the number of people hospitalised
or working days lost but caused one case of Guillian-Barré syndrome (a
major neurological condition leading to paralysis) for every one million
vaccinations. Fifteen of the 36 trials were funded by vaccine companies
and four had no funding declaration.
Our results may be an optimistic
estimate because company-sponsored influenza vaccines trials tend to
produce results favorable to their products and some of the evidence
comes from trials carried out in ideal viral circulation and matching
conditions and because the harms evidence base is limited..
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