The Sunday Mail
Catherine Murombedzi
THE media is awash with news of the HIV vaccine trial which was stopped in South Africa last month.
The quest to find a lasting solution to the spread of HIV, the virus that causes Aids, lay in the vaccine trial network known as HVTN 702. The vaccine was under trial for 18 months.
However, the vaccine was found not to prevent HIV transmission. It was hence stopped with immediate effect.
In a report, the National Institute of Allergy and Infectious Diseases (NIAID) announced the HVTN 702, a large-scale HIV vaccine efficacy trial of a canary pox-based vaccine, was stopped because it failed to prevent HIV.
“HVTN 702, also known as Uhambo journey of hope, was stopped following a scheduled review by the Data Safety Monitoring Board (DSMB), an independent data and safety monitoring board.
“The review showed no significant difference between the two arms of the trial and importantly, no safety concerns. Trial participants are being informed of the stop and will remain in the study for follow-up,” read the report.
A local researcher with the University of Zimbabwe College of Health Sciences — Clinical Trials Research Centre (UZ-CHS-CTRC), Dr Portia Hunidzarira, on Monday explained the vaccine roadmap.
“Vaccines take long to be rolled out as safe for human use. Despite the HVTN 702 vaccine being stopped, a lot has been learnt from the trial. It was found that it did not prevent HIV hence it was stopped. This trial, HVTN 702, also known as Uhambo, is a Phase 2B/3 study.
“Uhambo was testing a regimen adapted from the vaccine strategy tested in the RV144 Thailand. It sought to boost the Thai vaccine trial which showed about 31 percent lower infection rate among volunteers who received the vaccine versus those who received the placebo,” said Dr Hunidzarira.
Uhambo had 5 407 participants selected randomly between the ages of 18-35 years.
Dr Hunidzarira explained that they were each given six injections over 18 months and a total of 252 HIV infections were reported in the trial.
“Of this, 129 were on the effective vaccine arm, with 123 on the placebo. All study participants received a comprehensive HIV prevention package which included pre-exposure prophylaxis (PrEP) and other prevention methods,” said Dr Hunidzarira.
A trial has two arms, a vaccine on one hand and a placebo on the other. Wikipedia defines a placebo as saline-based water solution. Participants in any trial are blinded with users not in the know. They are unblinded and informed after the trial.
The South African Ethics Committee was informed of the Uhambo result. Some people may argue that the trial failed, however, science and research does not view it so.
Any clinical trial has two prongs — Uhambo has informed science on the way forward. Participants are now undergoing further counselling, prevention and treatment for those in need. The study will close next year.
“The study has not been a failure, the trial was a success as clinicians got an answer that HVTN 702 does not prevent HIV acquisition,” said Dr Hunidzarira.
A vaccine is a safe method ensuring any pandemic is under control. Science has been working round the clock on an anti-HIV vaccine. Vaccines take long with the polio vaccine having taken 47 years.
The first case of HIV was noted in the USA in 1982 with Zimbabwe recording its first case in 1985. The spread of the HIV virus saw the global village under threat as new infections spread.
Anti-HIV medication commonly referred to as anti-retroviral therapy (ART) has brought a new lease of life for people infected with HIV. With correct medication and adherence, the HIV virus is suppressed to undetectable levels. Undetected HIV cannot be transmitted. So far, there is no cure for Aids, the disease caused by HIV.
With no cure, a vaccine is required to halt further spread of the virus. The termination of HVTN 702 does not affect other trials or any other HIV prevention efficacy trials taking place globally.
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