- Yet another HIV vaccine bites the dust.. Rather oddly they took another month to discontinue vaccinating volunteers in South Africa. Also the spokeswoman for the trials describes the failure as "a sad day for the industry". Maybe I am mis-understanding her, but that seems quite a self-centred viewpoint to take. It seems there are more than two dozen vaccines being tested for safety in human trials and only one of those is ready for testing its efficacy.
- A shocking article linked to the discontinued vaccine : people vaccinated with the Merck vaccine may actually be at an increased risk for contracting HIV. Of the more than 3000 volunteers vaccinated with the experimental vaccine- they found 24 cases of HIV infection as compared to 21 in the placebo group. I do not know the significance of the data (and it appears neither do the experts so far)- but Merck and NIAID are quick to reassure the public that the vaccine itself is incapable of causing infection. A spokesperson from the AIDS vaccine advocacy coalition hopes that this data will not scare away future volunteers for prospective HIV vaccines.
- The CDC now recommends regular HIV testing for TB patients. This follows data from 2005 that show that almost 1/3rd TB cases have not been tested for HIV. Of those tested in 2005 13% were HIV positive.
Saturday, 27 October 2007
HIV news
Subscribe to:
Post Comments (Atom)
1 comment:
This is with respect to the finding that Merck's HIV vaccine might have increased risk to HIV.
I don't think this is a necessarily accurate interpretation of the data. The data from the trial showed that 24 people in the Vaccinated group became HIV infected, whereas 21 people getting placebo developed HIV infection.
This does not imply that the vaccine, by itself, increases the risk of HIV infection. The article and others picking up this story are re-interpreting the existing data to suggest that the vaccine makes you either more susceptible to HIV or causes HIV. I would hazard that neither is a likely explanation.
It seems more likely, that patients in the vaccinated group might have been in some way more susceptible to acquiring HIV prior to the study (either through risky sexual behaviour) or that they might have believed that getting the vaccine might protect them and therefore indulged in high risk sexual activity. There has been evidence of this sort of bias in studies involving circumcision, where men post-circumcision increase their frequency of risky sexual activity assuming they would be protected against developing HIV as a result of being circumcised.
Although we shall not know until all the data from the Merck trial is published and reviewed, it would be a huge setback to the entire HIV program if the vaccine did increase HIV risk.
Post a Comment