Merck’s HIV Vaccine Makes People More Likely to Develop AIDS

Dog Flu | Nov 7, 2007

It is being reported that study participants who were given an experimental Merck HIV vaccine maybe more susceptible to the virus as a result.

Merck, along with the National Institute for Allergy and Infectious Diseases and the HIV Vaccine Trials Network, gave up on the experimental vaccine after clinical trials of the vaccine showed little promise.

In analyzing the data from one such trial, Merck learned that a group of participants who received the vaccine, acquired HIV at a greater percentage than did a group of participants given a placebo.

“What is scary is that we’re no closer than we’ve been for a while to the development of an HIV vaccine, which we desperately need globally and locally,” said Dr. Bob Wood, director of HIV/AIDS Control Program for Public Health — Seattle & King County. “And if this vaccine actually increased people’s risk of acquiring HIV, it might be very difficult to recruit people into future vaccine studies.”

The vaccine used a disabled form of a common-cold virus to carry three synthetically produced HIV genes
into the body. It was hope that those genes would result in the body creating an immune response using killer “t” cells.

“That is the leading hypothesis — that the vector causes production of more CD4 cells that the virus could infect,” said Dr. Keith Gottesdiener, vice president for clinical research at Merck

“Among the 778 male volunteers who had high levels of pre-existing immunity to adenovirus 5, 21 cases of HIV infection were observed in those who had received vaccine and nine cases of HIV infection were observed in the volunteers who had received placebo,” Merck said in a statement.