Antibody clues to AIDS vaccine success (AFP)

Antibody clues to AIDS vaccine success

The success of an AIDS vaccine trial that in 2009 was shown to protect 31 percent of people studied may have been due to varying levels of antibody responses in the patients, researchers said Thursday.

Different types of antibody responses were associated with who became infected and who did not, according to an analysis of the results published in the April 5 edition of the New England Journal of Medicine.

For instance, a type of antibody produced by the body to ward off infection, known as IgG, could attach itself to the surface of the HIV protein and appeared to help prevent infection in some people.

People received the vaccine and whose IgG antibodies were able to bind to this region, called V1V2, showed lower infection rates than the placebo group.

On the other hand, patients whose blood tests showed the highest levels of a different antibody, IgA, appeared to have less protection against HIV than people with lower levels, leading scientists to think it may have actually interfered with the vaccine and made it less effective.

http://news.yahoo.com/antibody-clues-aids-vaccine-success-160834400.html