New method for HIV vaccination?
Scientists have developed a possible way to immunise animals against HIV using the common cold virus. So far it has been tested in guinea pigs, and seems to be effective against a wide range of HIV strains.
Scientists have faced two major problems in attempting to immunise against HIV. Using the actual virus to produce a vaccine (as with other viruses such as measles) is too dangerous, and HIV mutates rapidly. Mutation is problematic as it can change the shape of the virus dramatically, so the immune system is no longer able to recognise it.
So the team studied the virus to locate a region that was crucial to its function, and unlikely to be altered as the virus mutates. But such a small region by itself would not activate the immune system. So to activate a response, they needed to use another virus to introduce the HIV segment. They used the rhinovirus which causes the common cold.
This technique is quite complex, as the shape of the HIV segment must stay the same to allow the immune system to recognise it. The process involved systematically testing millions of ways of combining the HIV segment with the rhinovirus to discover the best method.
Although the guinea pigs seemed to be protected against a large number of HIV types, the response was very small and slow. But the results prove that the technique has potential and warrants further investigation.