Another Disappointment For an HIV Vaccine but There Is Hope
By Heather Boehner.
An experimental vaccine regimen did not protect young women from acquiring HIV in a large study in sub-Saharan Africa, adding to a long string of disappointments in HIV vaccine research.
The Imbokodo trial-tested a primer vaccine dubbed AD26.mos4. HIV uses an adenovirus vector similar to the used in the Johnson and Johnson COVID -19 Vaccine.
It delivers a computer-designed mosaic of antigens from multiple HIV strains. This is followed by a second vaccine containing HIV envelope proteins.
Starting in 2017, the study recruited more than 2600 women at high risk for HIV>. They were randomly assigned to receive six vaccine or placebo shots over the course of a year. In an analysis after the first dose, 51 participants who received the vaccine regimen and 63 of those who received the placebo injections acquired HIV. The vaccine reduced the risk of HIV infection by just 25%-far below the 50% effectiveness threshold researchers were aiming for.
This is the second HIV vaccine trial failure in two years. Only one large study, the Mosaico trial is underway, testing a similar vaccine regimen for gay, bisexual men, and transgender women.
"The development of a safe and effective vaccine to prevent HIV was proven to be a formidable scientific challenge," says the National Institute of Allergy and Infectious Diseases Director Anthony Fauci, MD.
"Although this is not certainly the study outcome for which we had hope, we must apply the knowledge learned from the Imbokodo trial and continue our efforts to find a vaccine that will be protective against HIV."
Comments