Preventative HIV vaccine candidate triggers desired immune responses

Monday, 09 Jul, 2018

Dr. Dan Barouch, Professor of Medicine at Harvard Medical School and author of the study, told Newsweek he is "cautiously optimistic" about the results, but stressed there are many obstacles to overcome before a vaccine is rolled out for humans.

"We have to acknowledge that developing an HIV vaccine is an unprecedented challenge, and we will not know for sure whether this vaccine will protect humans", he said. It's one of just five vaccines to ever make it that far in testing, but those that have weren't effective enough to go further.

Other researchers caution seeing this vaccine as the final solution to the virus.

To address these methodological issues, the scientists evaluated the leading mosaic adenovirus serotype 26 (Ad26)-based HIV-1 vaccine candidates in parallel clinical and pre-clinical studies to identify the optimal HIV vaccine regimen to advance into clinical efficacy trials.

The team created a mosaic-style vaccine by taking parts from different HIV viruses and combining them.

Dr Brady added that in the meantime there were already tools that were effective for preventing the disease from spreading, such as contraception and treatments for HIV-positive people that prevent them from passing on the virus. The HIV vaccine has produced an favorable immune system response when tested on 393 people, according to the Lancet.

A new study has given the researchers a ray of light in the battle to safeguard people from the most widespread virus, HIV-1. In a world with HIV and AIDS is home to around 37 million people.

With that said, it doesn't necessarily mean that the patients are incapable of contracting HIV - and it would be unethical to try to infect them with the virus to find out.

The Ad26/Ad26 plus gp140 vaccine candidate induced the greatest immune responses in humans and also provided the best protection in monkeys - resulting in complete protection against SHIV infection in two-thirds of the vaccinated animals after six challenges.

To test the vaccine, the team gathered nearly 400 adults with HIV aged between 18 to 50 from 12 clinics in southern and eastern Africa, Thailand and the U.S.in 2015. The participants were treated in clinics in east Africa, South Africa, Thailand, and the U.S., and either received a placebo or one of seven vaccine combinations.

It has also helped to protect monkeys from the virus similar to HIV. Scientists must await the results of this trial find out whether the vaccine cannot only provoke an immune response, but actively protect against HIV.

Participants in the research were selected from 12 clinics in East Africa, South Africa, Thailand, and the USA.

All of the vaccines prompted anti-HIV immune responses in the participants, the results revealed.

We have no evidence so far that it will actually work in the field, so it's important to be cautious interpreting these early results. It's unclear whether it would provide protection in humans.