New HIV vaccine targets virus envelope protein

Since the discovery of HIV in 1981, researchers have tried several strategies to eradicate this life-threatening infection. However, creating a HIV vaccine is laborious due to the complex structure of this virus. Now thanks to an EU- Funded project, researchers were able to develop a vaccine that targets gp41, an envelope protein. Gp 41 is part of the structure of the viral envelope along with gp120; because these glycoproteins help the virus to fuse with target cells of the host, there were considered one of the keypoints of a potential treatment of AIDS, especially gp120.

Now researchers have thought that if they integrated gp41 into the vaccine, they would be able to trigger an immune response that prevents penetration of HIV in human cells. Nicolas Mouze, chief scientific officer at PX’Therapeutics, one of the project partners, explained that they used an innovative approach that combined protein engineering, specific vaccine formulation and a combination of multiple routes of administration.

Alexandru Rafila, Chairman of the Romanian Society for Microbiology in Bucharest, gp41 is not an absolute novelty in the long history of the development of a vaccine against HIV. However, Rafila added that it is a meaningful approach that could result in a vaccine that would trigger an immune response. The problem is that HIV attacks not only T lymphocytes, that are essential components of the immune system but also other immune cells. It seems the latter are infected not only through gp41 but also by other mechanisms. This is why, according to Rafila, an effective vaccine would prevent infection of any other cells.

However , there are researchers who call into question other issues such as HIV diversity and its enormous capacity to mutation. Ulrich Fruth, a vaccine development and evaluation team leader at the World Health Organisation in Geneva, Switzerland, said the idea is that a vaccine should induce antibodies T cells immune response that would attack  HIV in all of its forms.

Although this strategy aims a viable approach, Fruth believes that the success of such a vaccine is difficult to predict. He pointed out that they do not know if the project is successful and he stressed that they were more successful in trials with humans. However it seems that it is too early to draw conclusions because clinical safety studies showed a relatively low effect. In addition, Fruth pointed out that a limitation of the vaccine is that it targets only the antibodies; in order that a vaccine to be effective, it should target both T cells and antibodies, believes Fruth.