New HIV vaccine enters trials


By Calder Phillips-Grafflin

For years, the holy grail of vaccine research has been developing a vaccine for HIV/AIDS. It’s the perfect target for a vaccine; HIV is hard to treat once infected, easily spread and almost always inevitably fatal. A successful vaccine would prevent millions of new HIV infections, likely saving millions of lives in Africa and Asia.

Just this week, the FDA (Food and Drug Administration), in charge of authorizing drug tests, approved the first phase of human testing of a new HIV vaccine developed in Canada. What’s important about this vaccine is that it’s the first HIV vaccine developed from a complete (but dead) copy of the HIV virus. Almost all of the vaccines we use today are ‘full-virus’ designs, but all previous (and unsuccessful) efforts at an HIV vaccine have used partial copies of HIV instead.

Efforts to build an HIV vaccine started in the early 1990s, but were stalled as researchers continued to discover new strains of HIV that were already resistant to the techniques used by their vaccines. It took almost a decade for the first of these vaccines to make it to testing in humans, but those tests were quickly halted by the FDA.

Setting a pattern of failure that’s lasted for a decade, AIDSVAX had been extremely successful in tests on animals, but when time came to test on humans, not only did the vaccine not work, but questions were raised about the possibility of people becoming infected from the vaccine itself. It’s one thing to get the flu from a flu shot; it’s an entirely different thing to get an incurable and easily transmittable disease like HIV.

Just a few years later, this process was repeated in the STEP Study. Like AIDSVAX, STEP had been successfully tested in animals, but when time came to test it on humans, field tests suggested that people treated with the vaccine were more likely to contract HIV than those who weren’t treated.

Like previous attempts, the new Canadian vaccine has been very successful in animals, but testers aren’t taking any chances; the safety testing will be done on otherwise healthy HIV patients.




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