Test for best potential HIV/AIDS vaccine in the pipeline

Scientists in Britain are well on the way to developing a test for the best potential HIV/AIDS vaccine.

The test promises to be able to detect not only whether a vaccine will generate a response from the body's immune system, but also whether this response will be effective in actively fighting HIV.

At present there are few means of establishing whether a vaccine is likely to work without conducting large-scale clinical trials, but taking all candidate vaccines to a full trial is a costly exercise which can cost millions, take years and involve thousands of volunteers.

The new test, which is known as a viral inhibition assay, has been developed by scientists at Imperial College London and the International AIDS Vaccine Initiative (IAVI) and is being evaluated in a phase-one AIDS vaccine trial and preliminary results already indicate that the test can distinguish between immune responses that can control HIV and those that cannot.

The test involves blood taken from uninfected patients who have been injected with a candidate vaccine, which is then mixed in a laboratory with a live virus to see whether the immune cell responses prevent the virus from replicating.

The test was developed at IAVI's human immunology laboratory at the Chelsea and Westminster Hospital in London and the scientists hope that it can be used to check candidate vaccines, helping to pick out the most promising for full trials while dismissing ineffective products that could prove a considerable waste of time and money.

The project is funded by a £40 million grant from the Department for International Development to IAVI, which operates in 24 countries, for its work on HIV/AIDS research.

The development of the test comes after the failure of Merck's V520 vaccine, which had shown promise in triggering an HIV-specific immune response but was later found to offer no protection against HIV and may even have left some people more susceptible to the virus.