E-DRUG: HPV vaccine
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Dear e-druggers,
The new HPV vaccine is presented as a major breaktrough in the prevention of cervical cancer.
Here are articles from the Guardian commenting on the vaccine manufacturer lobbying strategies.
http://www.guardian.co.uk/medicine/story/0,,2042653,00.html
http://www.guardian.co.uk/frontpage/story/0,,2042960,00.html
In our organization we are presently conducting a systematic review of the efficacy of this vaccine. Amazing as it may sound, only results from phase II trials have been published in the peer-reviewed scientific literature, and these report only on intermediary outcomes such as prevention of infections with HPV -specific types (the vaccine covers only 4 HPV types). A few conference abstracts report on the efficacy of the vaccine on precancerous cervical lesions, but only due to vaccine type. (conference abstracts provide limited data and are not peer-reviewed). There are no published data on the efficacy of the vaccine on the most clinically meaningful endpoints such as the population impact : prevention of precancerous cervical lesions - regardless of the HPV-type involved.
On the other hand, very large clinical trials have been conducted or are still ongoing. Data on the efficacy of the vaccine on the overall prevention of pre-cancerous cervical lesions do exist but have not yet been published in the scientific literature. Some can be accessed for instance on the FDA website; where the efficacy does not look nearly as good as some try to make us believe -(and not as good as predicted from efficacy on preventing HPV infection)
- although the vaccine definitely has some benefits.
In a population of fully vaccinated participants, not yet infected with HPV, overall vaccine efficacy in preventing Cervical Intraepithelial Neoplasia (CIN) grade 2 or above, (whether due to HPV type included in the vaccine, or not) was 39% (95% Confidence interval: 23-52) . This means than in clinical trials, the vaccine prevents a bit more than one third of precancerous cervical lesions.
Could we start a debate on the following issues:
- Many countries are already recommending vaccination for young girls - or even boys, such as Austria. Can such important decisions be based on published data only from phase II trials? Or unpublished data? (never submitted to scientific scrutiny?) (we are specifically looking for the basis for decision making in other countries)
- It seems to me that data on the population impact of the vaccine could have been published by now if there was a real willingness to do so, and I wonder if there is much interest from the firm in publishing results that might weaken the current enthusiasm, carefully engineered, over this vaccine. Are there any rules, on delays between completing a trial, and publishing results?
(so: http://www.fda.gov/ohrms/dockets/ac/06/slides/2006-4222S-1.ppt#73)
Marie-Laurence Lambert, MD, PhD
KCE
Centre d'Expertise des Soins de Santé
Federaal Kenniscentrum voor de Gezondheidszorg
Belgian Centre for Healthcare Knowledge
62 Rue de la Loi
1040 Bruxelles
Belgique
Tel (32) 2 287 33 45
Fax (32) 2 287 33 85
http://kce.fgov.be/
"Lambert Marie" <Marie.Lambert@kce.fgov.be>