HIV Vaccine Trial Cancelled in a Setback for AIDS Research

80beatsBy Eliza StricklandJul 18, 2008 6:51 PM


Sign up for our email newsletter for the latest science news

In a sign of the slow progress in the medical fight against the HIV virus and AIDS, a federal health agency has canceled plans for an ambitious clinical trial of an experimental HIV vaccine. Although this candidate vaccine was once thought very promising, researchers lost confidence in it after

Researchers at the National Institute of Allergy and Infectious Diseases had hoped to begin enrolling 8,500 volunteers in the vaccine trial last fall, but the trial was

the failure last September of a similar candidate from drugmaker Merck & Co. that may have left some volunteers more vulnerable to HIV infection [San Francisco Chronicle].

postponed after the Merck vaccine was shown to be failing in its two main objectives: to prevent infection and to lower the amount of H.I.V. in the blood among those who became infected.... After a safety monitoring committee detected the problems with the Merck vaccine in September, the company quickly halted its study [The New York Times].

Both the Merck vaccine and the new experimental vaccine use the common cold virus, Adenovirus-5, to carry the vaccine's payload. That approach is now in question, as the Merck trial showed that those who had been previously exposed to the Ad-5 cold virus were more at risk of being infected with HIV.

The disappointing end of the Merck trial has led agencies to renew their emphasis on basic research, rather than on large and costly clinical trials, in hopes that the research will lead to better vaccine candidates for future testing. But it has also prompted some to declare that the vaccine field is in serious trouble; in March, virologist Robert Gallo said the [Merck] results were a catastrophe comparable to the space shuttle Challenger disaster [Nature News].

Although the large clinical trial has been canceled, researchers will go forward with a scaled-down experiment that will study whether the vaccine can lower the amount of HIV in the blood of an infected person. But this downsizing troubled some activists:

"After a year of public hand-wringing and unproductive public attacks on the search for an AIDS vaccine, it is essential this decision not be viewed as a vote of no-confidence," said [AIDS activist] Mitchell Warren [The Wall Street Journal].

Image: iStockphoto

1 free article left
Want More? Get unlimited access for as low as $1.99/month

Already a subscriber?

Register or Log In

1 free articleSubscribe
Discover Magazine Logo
Want more?

Keep reading for as low as $1.99!


Already a subscriber?

Register or Log In

More From Discover
Recommendations From Our Store
Shop Now
Stay Curious
Our List

Sign up for our weekly science updates.

To The Magazine

Save up to 70% off the cover price when you subscribe to Discover magazine.

Copyright © 2022 Kalmbach Media Co.