By Josephine Chinere:
At the moment, much needed resources and research efforts are rightly going towards Covid-19 vaccines and even treatment.
Reports indicate that there are many studies underway to find the cure or vaccine for Covid-19 since it was first discovered last December. As of March this year, 260 studies were listed in the World Health Organisation (WHO) registry platform for Covid-19.
The print, online and electronic media platforms are also awash with Covid-19 stories and updates.
But while there is a need for Covid-19 research, it is also important not to erase other important public health issues, such as HIV. Let us not let Covid-19 make us abandon the efforts we have put into HIV research and implementation and stall the progress made this far.
Recently, WHO estimated that amidst the Covid-19 chaos, “a six-month disruption of antiretroviral therapy could lead to more than 500,000 extra deaths from Aids-related illnesses, including from tuberculosis, in sub-Saharan Africa in 2020–2021.”
Lest we forget, this is HIV Vaccine Awareness Day and commemoration month! We commemorate World HIV Vaccine Awareness on May 18 every year.
This day is a chance to thank the volunteers, community members, health professionals and scientists working together to find a safe and effective preventive HIV vaccine. It is also a time to educate communities about the importance of preventive HIV vaccine research in the context of 1.7 million new HIV infections last year.
Pre Exposure Prophylaxis (PrEP), voluntary medical male circumcision and treatment are all effective HIV prevention methods but they have not been enough to get us over the line to epidemic control.
In summary, vaccine research starts in the laboratory. Next, the vaccines are tested on animals. If it shows evidence of safety and potential efficacy in animals, it moves on to testing in humans. This starts in small trials and, if results show the vaccine is safe and causes beneficial immune responses, it moves on to larger trials.
The last stages of the process involve efficacy trials, named Phase IIb or Phase III trials. Thousands of volunteers participate. Without them, it would be impossible to learn if the vaccine lowers people’s risk of getting HIV.
Researchers are working to come up with two kinds of vaccines against HIV. A preventive vaccine, would reduce HIV risk in people who are HIV negative. It would teach their immune systems to recognise the virus right away (for example, during sex), and block it from causing an infection. No preventive HIV vaccine exists yet.
A therapeutic HIV vaccine is also being pursued. People living with HIV would take a therapeutic vaccine to strengthen their immune systems for better control of the virus. This kind of vaccine could, in theory, help people control the virus without anti-retroviral drugs (ART). Research on therapeutic vaccines may also inform research on how to cure HIV. No therapeutic HIV vaccine has been proven to work yet.
“A safe and effective HIV vaccine is needed now more than ever. Now is not the time for us to turn our backs on HIV vaccine research and development,” says Maureen Luba, an HIV prevention advocate with Aids Vaccine Advocay Coalition (Avac).
“There is a clear, urgent and ongoing need for a safe and effective HIV vaccine. New HIV infections continue unabated in many parts of the world and populations.”
HIV vaccine research is more productive than ever, with multiple large-scale vaccine trials underway and dozens of promising vaccine approaches in development.
Malawi is one of the countries that is participating in the Imbokodo HIV vaccine study alongside Mozambique, South Africa, Zambia and Zimbabwe. The study aims at finding out if the vaccine is safe and could prevent HIV infection.
In 2009, a trial in Thailand called RV144 showed that volunteers who got the test vaccine were 31 percent less likely to get HIV during the trial than those who got the placebo (a harmless, fake or “dummy” vaccine).
The Thai trial results showed that the vaccine was protective against some exposures to HIV. Since that trial, researchers identified some of the immune responses that might have led to protection.
They also came up with adjustments that they thought would improve the Thai vaccine and adapted it for use in other parts of the world. The outcome was the Uhambo trial (HVTN 702) in South Africa.
But unfortunately, in February, Uhambo vaccinations were stopped early because data showed the vaccine did not prevent HIV acquisition. It neither increased nor decreased the risk of acquiring HIV. The vaccine was safe but not effective. Although vaccinations were stopped, participant follow-up continues and will continue for a year.
The Uhambo participants’ safety will be closely monitored during the follow-up period and researchers hope to learn and understand why the vaccines did not work to prevent HIV infection. Participants will also continue to receive HIV counselling and HIV testing during the follow-up period.
Stoppage of vaccinations in Uhambo was informed by the recommendations of an independent body known as the Data and Safety Monitoring Board, which reviews all data regularly to ensure the safety of participants and determine if the study should continue.
The HIV vaccine studies have also greatly contributed to research into other diseases. For instance, HIV research has generated more scientific knowledge about immune function and responses than ever existed, greatly advancing understanding of Covid-19.
The rapid development of many Covid-19 vaccine candidates is built on techniques and platforms developed through HIV vaccine research to map virus structure and build robust immune responses.
HIV research also pioneered the field of antiretroviral treatments, in parallel with vaccine research. This same dual approach is happening now, including the evaluation of some HIV treatments for possible use against Covid-19.
Above all, let us remain hopeful that someday, an effective HIV vaccine (and Covid-19 vaccine!) will be found and this will put to rest the HIV epidemic. A vaccine is needed for a durable and sustainable end of the HIV epidemic.
*Josephine Chinele is a 2019 Avac fellow at Pakachere Institute of Health and Development Communication