'safe' virus proposed as vaccine

A company is planning to inject people with an HIV vaccine made of the deadly virus itself, albeit a deactivated version.

Vaccines against many viruses, including flu, are made from deactivated versions of those viruses, but such an approach was previously dismissed as too risky in the case of HIV.

Now VIRxSYS of Gaithersburg, Maryland, is resurrecting the controversial approach, thanks to successful tests of a similar vaccine against SIV – also known as simian HIV – in monkeys.

"We said 'let's use HIV against itself', and that's what we're doing," says Gary McGarrity, VIRxSYS's vice president of scientific and clinical affairs.
High-profile flop

The idea of turning to the virus itself follows years of frustration with prospective vaccines based on viruses other than HIV, such as adenoviruses that cause colds.

Adenoviruses have been modified to carry parts of the HIV virus. Although there were hints of modest success with one such vaccine last year, the previous best bet proved to be a high-profile flop in 2007, during a trial dubbed "STEP".

Crucially, the new tests in monkeys suggest a vaccine based on HIV itself might be more effective than these attempts. The company is planning to apply for approval to perform human trials.

VIRxSYS says such trials would initially be only in people who already carry the virus, rather than in healthy people at risk of infection. This will certainly make for a less controversial trial, as it would avoid any chance of the vaccine going "live" and infecting people who didn't have HIV to start with.


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