HIV antibody breakthrough for SA scientists

2012-10-22 09:16
Zinhle Mapumulo
South African scientists have made a ground-breaking discovery that will bring them closer to developing an AIDS vaccine.

They have discovered a unique feature in the outer covering of the virus in two HIV positive women, which enabled them to make rare antibodies – known broadly as neutralising antibodies – that can kill up to 88% of HIV strains from around the world.

While these antibodies were identified three years ago in other studies it was not known how the human body was able to make them until laboratory studies conducted by scientists at the National Institute for Communicable Diseases (NICD), Dr Penny Moore and Professor Lynn Morris, discovered that a sugar (known as a glycan) on the surface protein coat of the virus at a specific position makes it vulnerable and enables the body to mount these antibodies.

Morris and Moore are part of the the CAPRISA consortium, led by Professor Salim Abdool Karim.

The consortium has been studying how certain HIV-infected people develop very powerful antibody responses for over five years.

Said Abdool Karim: “Broadly neutralising antibodies are considered to be the key to making an AIDS vaccine.

“This discovery provides new clues on how vaccines could be designed to elicit broadly neutralising antibodies. The world needs an effective AIDS vaccine to overcome the global scourge of AIDS,” he said.

Said Morris: “We were surprised to find that the virus that caused infection in many cases did not have this antibody target on its outer covering.

“But over time, the virus was pressured by the body’s immune reaction to cover itself with the sugar that formed a point of vulnerability, and so allowed the development of antibodies that hit that weak spot.”

» This story was updated after first published.