NIAID will not move forward with the PAVE 100 HIV Vaccine Trial

Jul 17, 2008

After soliciting and considering broad input from the scientific and HIV advocacy communities, the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), has determined that it will not conduct the HIV vaccine study known as PAVE 100.

However, NIAID believes the vaccine developed by its Vaccine Research Center (VRC) is scientifically intriguing and sufficiently different from previously tested HIV vaccines to consider testing it in a smaller, more focused clinical study. Therefore, NIAID will entertain a proposal for an alternative study with one specific goal: to determine if the vaccine regimen significantly lowers viral load—the amount of HIV in the blood of vaccinated individuals who may later become infected with HIV.

The original PAVE 100 study, as presented to NIAID's AIDS Research Advisory Committee in January 2007, proposed to test the VRC's HIV vaccine regimen in a trial initially designed to enroll 8,500 volunteers in the United States, South America, the Caribbean and Eastern and Southern Africa. The study was to begin U.S. recruitment in October 2007 but was postponed last fall following the decision to halt immunizations in the STEP HIV vaccine study. That decision was made after it was determined that the vaccine used in the STEP trial, an investigational product developed by Merck & Co. Inc., failed to prevent HIV infection or reduce viral load.

Subsequent analyses of the STEP trial found increased numbers of HIV infections among those volunteers who received the vaccine in comparison to those who received the placebo; the Merck vaccine itself did not cause HIV infection. The highest risk of HIV infection among vaccinees compared with placebo recipients appeared to be among males who were both uncircumcised and had pre-existing neutralizing antibodies to adenovirus type 5 (Ad5), the common cold virus used in the vaccine as a carrier for the HIV genes. Vaccination resulted in no apparent increased risk in men who were circumcised and who lacked pre-existing neutralizing antibodies to Ad5. The VRC vaccine regimen that was to be tested in the PAVE 100 study has two components, one of which includes an Ad5-based carrier, which is administered to boost immune responses that are first stimulated with a DNA vaccine.

Based on the analyses of the STEP study results, PAVE 100 was redesigned and reduced somewhat in its proposed scope, although it remained a scientifically and logistically complex study. The redesigned PAVE 100 study would have involved testing the VRC vaccine in 2,400 U.S.-based, circumcised men who have sex with men and who lack preexisting neutralizing antibodies to Ad5. The redesigned study would have tested the vaccine's effect on viral load, provided additional safety information about the product, and examined in detail immune responses to the vaccine and their impact on viral load.

Based on the available scientific information, NIAID has decided that the VRC vaccine regimen did not warrant a trial of this size and scope and that PAVE 100 will not proceed. However, NIAID will entertain a smaller, more focused clinical trial designed to answer one important question: Does the product have a significant effect on HIV viral load? If such an effect is noted, then additional studies or expansion of the study to carefully examine immunological correlates could be performed. NIAID will consider such an alternative study and will announce its decision at a later time.

Source: National Institute of Allergy and Infectious Diseases

Explore further: A fresh setback for efforts to cure HIV infection

add to favorites email to friend print save as pdf

Related Stories

NIAID creates HIV vaccine discovery branch

Jun 25, 2008

To accelerate the translation of basic discoveries about HIV into advances in vaccine design and evaluation, the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), ...

Consortium to design human trials of mosaic HIV vaccine

Oct 18, 2010

Los Alamos National Laboratory researcher Bette Korber is part of an international team of investigators working to design and implement the first human trial of a mosaic HIV vaccine candidate. The vaccine represents a novel ...

Study finds genital herpes vaccine ineffective in women

Sep 30, 2010

An experimental vaccine intended to prevent genital herpes disease in women, although generally safe and well-tolerated, proved ineffective when tested in the recently concluded clinical study known as the Herpevac Trial ...

Human clinical trial of DNA-MVA HIV vaccine candidate begins

Sep 28, 2010

A Phase I study, called RV262, recently began to evaluate a combination DNA prime/MVA vector boost vaccine regimen that was developed to protect against diverse subtypes of HIV-1 prevalent in North America, Europe, Africa ...

Recommended for you

Cambodia orders probe into mass HIV infection

44 minutes ago

Cambodian Prime Minister Hun Sen on Thursday ordered a probe into an apparent mass HIV infection believed to have been spread by contaminated needles, as the number of suspected cases passed 100.

A fresh setback for efforts to cure HIV infection

13 hours ago

Researchers are reporting another disappointment for efforts to cure infection with the AIDS virus. Six patients given blood-cell transplants similar to one that cured a man known as "the Berlin patient" have ...

Cambodia village reports mass HIV/AIDS infection

Dec 16, 2014

Cambodian health authorities on Tuesday said more than 80 people—including children and the elderly—who tested positive for HIV/AIDS in a single remote village may have been infected by contaminated needles.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.