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Researchers Suggest Insufficient Evidence of Efficacy of
HPV Vaccine
March 11, 2009 by: David Gutierrez, staff writer
http://www.naturalnews.com/025817.html
(NaturalNews) There is not enough evidence to confidently state that two
popular vaccines against the human papillomavirus (HPV) will reliably prevent
against the development of cervical cancer, according to two articles published
in the New England Journal of Medicine.
"Despite great expectations and promising results of clinical trials, we still
lack sufficient evidence of an effective vaccine against cervical cancer," wrote
Charlotte J. Haug, editor of The Journal of the Norwegian Medical Association,
in the first article. "With so many essential questions still unanswered, there
is good reason to be cautious."
Haug noted that Merck's Gardasil and GlaxoSmithKlein's Cervarix have only been
studied clinically for six and a half years at the most, and have only been on
the market since 2006. This means that researchers still do not know if the
vaccines are effective
against HPV over the long
term, or what cancer-related side effects they might have. For example,
protecting the body from infection with certain HPV strains might have
unforeseen immunological side effects, reducing the body's resistance to other
varieties.
Due to the newness of both vaccines, it is also not yet been possible to see
whether they actually reduce
cervical cancer
rates. Normally, it takes years of HPV infection before
cancer can develop - more
time than either drug has been studied.
In the second article, a pair of Harvard researchers noted that HPV vaccination
is not necessarily a cost-effective way to protect against cervical cancer.
Current screening methods such as Pap smears have been very effective in
reducing the death rate of cervical cancer already, but such tests must continue
even after receiving an HPV vaccine. Even at their best, the vaccines do not
protect against all cervical cancer strains that can cause cancer; a woman who
has already been exposed to one of the strains in the vaccine will get no
benefit from it.
"I believe the vaccine is a great advance," said Philip Davies of the European
Cervical Cancer Association, "but we have to implement it properly to get the
benefits, and that hasn't happened."
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