Thursday, 21 February, 2019

Invented a vaccine against HIV, which has worked on people

AIDS activists light a group of candles placed in the shape of a red ribbon during an event marking World AIDS Day in Manila Invented a vaccine against HIV, which has worked on people
Melissa Porter | 10 July, 2018, 04:57

An experimental HIV vaccine showed promise of protecting healthy adults from contracting the deadly virus that killed millions of people in the past years.

Researchers recruited 393 people from a number of countries to take part in the trial.

A vaccine against HIV has been a real challenge for scientists, because of this virus many strains. Over a 48-week period, they were given four vaccines.

At the same time, a similar study was carried out in 72 rhesus monkeys so the results could be compared.

Mild side effects were common, and around 1% of people in the trial had more serious adverse reactions to the vaccine. It's one of only five experimental HIV-1 vaccine concepts that have gotten this far during the 35 years of the HIV pandemic.

This is a really encouraging finding. Thus, an HIV vaccine is needed badly. "Obviously, the search for an HIV vaccine is very elusive".

Where does the study come from?

"The challenges in the development of an HIV vaccine are unprecedented, and the ability to induce HIV-specific immune responses does not necessarily indicate that a vaccine will protect humans from HIV infection", said Barouch.

This study was supported by Janssen Vaccines & Prevention BV and the NIH, the Ragon Institute of MGH, MIT and Harvard, and a cooperative agreement between the Henry M Jackson Foundation for the Advancement of Military Medicine and the US Department of Defense. Their results were published in The Lancet.

What kind of research was this?

So far, a major limitation has been the lack of direct comparability between preclinical studies and clinical trials. In early human trials the vaccine has been found to be safe in humans.

Buchbinder said that she hoped "to validate our non-human primate model to see if it works for humans and if we see the same correlates of protection".

What did the researchers do?

In this study, the researchers aimed to evaluate mosaic adenovirus serotype 26-based HIV-1 vaccine candidates.

The researchers looked at several different modifications of the vaccine during the study to test out which might be the safest and most effective.

Based on the results from phase 1 and phase 2a clinical trials that involved almost 400 healthy adults in Rwanda, South Africa, Thailand, Uganda and the United States, a phase 2b trial has been initiated in southern Africa to determine the safety and efficacy of the HIV-1 vaccine candidate in 2,600 women at risk for acquiring HIV.

To stimulate, or "prime", an initial immune response, each volunteer received an intramuscular injection of Ad26.Mos.HIV at the start of the study and again 12 weeks later.

Sixty-seven rhesus monkeys were also given the vaccine, and the scientists found that it protected the monkeys against simian-human immunodeficiency virus.

This took place 6 months after they'd received all of their vaccinations. As the name suggests the disease targets the immune system of the body of the host and disarms the soldiers or immune cells of your body. No grade 4 adverse events or deaths were reported.

3d rendered HIV Virus in Blood Stream in color background. "But the data is promising and we are happy to report the immune response". It's unclear whether it would provide protection in humans. Two thirds of the tested monkeys' immune systems resisted the incoming infection proving the vaccine successful in them. Additionally, healthy participants were included in the trial, who were considered to be at low risk of HIV infection.

Despite the relatively good results from the human and animal trials, the researchers are careful not to be too confident in the potential vaccine.

As with most diseases, prevention is always better than cure.

The hope is that it could offer much better protection against the nearly unlimited number of HIV strains found across the world.

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