Latest HIV Vaccine Fails In The US, Government Stops Study
The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, announced that they will stop giving doses of this experimental vaccine.
The trial, which began in 2009 is the most recent in a line of unsuccessful HIV vaccine studies. The study, named HVTN 505, consisted of 2,504 participants in 19 different cities and was examining men who have sex with men, as well as transgender people who have sex with men. It was designed to measure whether the vaccine could prevent HIV infection and/or decrease the amount of HIV in the blood of vaccine recipients who contracted HIV.
The vaccine regimen consisted of three immunizations given over an eight week period. The strategy of the vaccine was to first prepare the immune system and then give a vaccine "boost". The vaccine was based on the common cold virus that was used to pass HIV genes into the body on the sly and capture the attention of the immune system.
The first examination looked at participants who were diagnosed with HIV after being involved in the study for just 28 weeks. This was done to allow sufficient time for the vaccine regimen to be administered and encourage an immune response.
The researchers found that 27 vaccine recipients developed HIV infections, compared to 21 who were given placebo.
Among the volunteers who developed HIV within the first 28 weeks of the trial, 14 were experimental vaccine recipients and 9 were placebo patients.
By the end of 24 months, 41 vaccine recipients had become HIV infected compared to 30 among the placebo recipients.
Additionally, the vaccine did not decrease the viral load among participants who developed HIV infection at least 28 weeks after beginning the study and who were tracked for at least 20 weeks after the diagnosis. There were 30 volunteers with a measurable viral load. 15 recipients, 15 placebos).
The study team plans to slowly work through the data they have collected to better analyze why the vaccine did not work. Researchers will continue to monitor all study participants for five years after the start of this trial.
To date, there are no vaccines that are proven to prevent HIV infection - HIV is the virus that causes AIDS.
In a separate study from earlier this month published in Nature, researchers from the Duke Human Vaccine Institute say they have discovered a new route that may help develop a vaccine to improve a person's ability to neutralize the HIV virus.
Written by Kelly Fitzgerald