Hope as study shows antibodies can be used in HIV prevention

Monday, August 16th, 2021 00:00 |
Cleopatra Wanjiku.

A recent breakthrough in research has proved that antibodies can be used to prevent HIV infections in humans.

According to a study by HIV Vaccine Trials Network (HVTN) AND HIV Prevention Trials Networks, which was launched in April 2016, it broadly neutralising antibodies (antibody responsible for defending cells from pathogens, which are organisms that cause disease) could prevent infections.

The Antibody Mediated Prevention study (AMP) is the first to test whether an infusion of antibodies, received every eight weeks, is safe and can prevent HIV infection.

VRC01, as the antibody was named, is a single, potent, broadly neutralising, monoclonal antibody (made by cloning a unique white blood cell). 

Collectively known as the AMP studies, two parallel prevention efficacy trials of VRC01 were launched in 2016 and enrolled a total of 4,600 people globally of different sexes and sexual orientations.

Each trial tested a higher and lower dose of VRC01, administered intravenously every eight weeks to evaluate it as a long-acting intervention against HIV versus a placebo. 

The AMP study consists of two Phase II (b) trials and their results were presented at HIV Research for Prevention Conference virtually on January 26, 2021.

It was reported that the VRC01 did not significantly reduce the overall risk of HIV acquisition in participants who received the antibody compared to those who received the placebo.

However, it safely and effectively reduces the risk of acquiring HIV from strains of the virus that are classified as “highly-sensitive” to it. 

The trials suggest a single broadly neutralising antibodies (bNAb), such as VRC01, does not offer sufficient protection against a broad range of HIV, and a combination of these antibodies is likely needed to achieve broad protection.

Susceptible strains 

“The AMP study was aimed at proving whether the HIV antibody called VRC01 can prevent people from getting HIV.

The finding is that it was safe, with a few side-affects but not strong- mild to tolerate within hours to two days after infusion.

The results showed there are strains susceptible to VRC01- about 30 per cent to  up to 75 per cent effective.

While there are 30 per cent that were susceptible, 70 per cent were not,” shared Dr Elizabeth Irungu, Senior Researcher, Kenya Medical Research Institute- Partners in Health Research and Development. 

Despite that new medical findings are not 100 per cent effective in HIV Prevention, the AMP study has opened a door to finding an antibody or combiation of which is more efficient using a wider range of strains. 

“The aim of the study was to prove that we can use antibodies to prevent infections of HIV.

And the study has proven that VRC01 works, but only by 30 per cent which is not so well.

But it has also opened a door to more research using antibodies. The idea is to create a cocktail that people can pick for use for as long as they are at risk.

The studies will be conducted in different parts of the world in larger scale. And the work will continue until we find a better solution,” added Dr Irungu. 

This concept has also significantly helped in the research for HIV vaccine, with the possibilities that antibodies can be used to create a vaccine for the virus.

Civil societies and women’s health champions share the hope that the AMP study brings, especially with the fact that women are disproportionately affected by HIV.

“There are so many reasons women and girls are disproportionately affected including, gender based violence, structural factors, biological and under empowerment.

The preventive options that exist is mostly the male condoms, and women in many cases have to negotiate for safe sex.

So the AMP gives hope that they can create more options to cover more women who are at risk,” shared Rosemary Mburu, the Executive Director Waci Health and Co-ordinator The Global Fund Advocates Network Africa, during her presentation at a recent science café by Media for Environment, Science, Health and Agriculture in Mombasa.

Virus suppression 

According to her, this research will go a long way in both the creation of a HIV Vaccine and in bringing hope for women in the search for more women control measures, especially considering the trial recruited many women both young and old.

Cleopatra Wanjiku, 28, the CEO of Pabaa Collection and Founder at The Voice of a Black Child, was informed about her HIV status at the age of 13 and had to immediately start taking ARVs.

Fifteen years later of both stigma and growth, the news of the AMP study brings so much hope for the future generations.

“It’s been quite long since the existence of HIV and this new breakthrough will definitely bring along changes.

The intake of ARVs helps in suppressing the virus, but if we can get this prevention for the virus, it would mean that in cases where some people are not adhering to their medication, hence transmitting the virus will ,therefore not be able to do so.

In the cases of mother to child transmission, we still haven’t eliminated it completely and this will help a great deal with mothers and children as well.

And to us who are living positively, it’s of course a big break knowing well that people are safe,” she shares.

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