By Phyllis Mbanje
AN African-led first HIV vaccine trial has given hope to millions of people who will only need a few shots to be immunised against the virus.
The clinical trial, running from 2018 to 2022 and dubbed PrEVacc, is being conducted in four African countries that include Zimbabwe as Africa takes the lead in the fight against the pandemic. The trial will be one of the highlights at the upcoming 10th conference on HIV science in Mexico.
Aids and TB director in the Health ministry Owen Mugurungi said the impact of the vaccine is remarkable and would go a long way in stemming the spread of the disease. “A vaccine is the cheapest way to manage any disease. Immunisation is better than treatment which is more expensive,” he said.
Zimbabwe has over the years experienced severe and perennial outages of antiretroviral drugs, a situation which can easily be corrected by an effective vaccine which will lessen the demand for drugs. “Everyone is looking forward to an effective vaccine which will save many lives and billions of dollars which are being spent on treatment,” Mugurungi said.
Although HIV prevalence in Zimbabwe has declined from 26,5% in 1997 to 14,3%, it is still considered too high and stakeholders are calling for scaling up of HIV prevention efforts.
Meanwhile, PrEPVacc, which is European-funded, is the first vaccine trial that attempts to incorporate pre-exposure prophylaxis (PrEP) in a realistic way, according to Eugene Ruzagira, a senior scientist who is leading the PreVacc trial.
According to Ruzagira, the pilot test will evaluate two experimental HIV vaccine combinations for the prevention of HIV infection, each compared against a placebo.
It will also evaluate whether a new formulation of the drugs used for PrEP (Descovy: tenofovir sulfonamides, TAF, plus emtricitabine, FTC) is as effective as the current formulation approved for PrEP (Truvada: tenofovir disoproxil fumarate, TDF, plus FTC).
Participants will be offered PrEP throughout the study to cover the period spanning the first three immunisations because scientists believe this is the best way for PrEP to be applied in an immunisation programme – protecting people until the vaccines have started working. When assessing vaccine efficacy in the PrEPVacc trial, only HIV infections that happen after the first three vaccines (given over six months) will be counted.
PrEPVacc will inform the field about whether the vaccine regimens can protect against HIV infection.
However, one of the challenges is addressing HIV-related stigma that can make it very difficult to find enough people willing to participate in HIV prevention trials.
“HIV vaccine trial participants may have to attend clinics where people living with HIV are treated, and may fear that people will think that they have HIV. I have worked with participants who did not want to be seen with our research teams or at our research clinics – even if they were HIV negative,” Ruzagira said.