By Faith Nyasuguta
The highly anticipated Johnson & Johnson’s HIV vaccine has failed to demonstrate sufficient protection in a clinical trial encompassing over 2,600 young women in sub-Saharan Africa, the firm and US health officials have said.
Despite the vaccine showing high safety levels with zero serious side effects, its efficacy in shielding beneficiaries from Human Immunodeficiency Virus (HIV) infection was slightly above 25 per cent.
Following this, the “Imbokodo” trial that commenced in 2017 will stop, and the participants, from Malawi, Mozambique, South Africa, Zambia, and Zimbabwe will be informed whether they received the vaccine or placebo.
However, the firm will still continue with a parallel trial including men who have sex with men and transgender individuals currently ongoing in Europe and in America where vaccine composition is different just like the prevalent HIV variants.
Paul Stoffels, the chief scientific officer of J&J in a statement thanked the women who participated in the trial and the company’s partners.
“While we are disappointed that the vaccine candidate did not provide a sufficient level of protection against HIV infection in the Imbokodo trial, the study will give us important scientific findings in the ongoing pursuit for a vaccine to prevent HIV,” he said.
“We must apply the knowledge learned from the Imbokodo trial and continue our efforts to find a vaccine that will be protective against HIV,” Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases which is a co-funder of the study, said.
The J&J HIV vaccine uses similar adenovirus technology to its Covid-19 vaccine and was delivered with four vaccinations over a year.
A genetically altered cold virus delivers genetic cargo carrying instructions for the host to develop “mosaic immunogens” — molecules capable of sparking an immune response to different HIV strains.
The last two doses further contained proteins often present on the HIV virus itself together with a substance dubbed “adjuvant” set to further trigger the immune system.
The J&J trial was examined two years after the women aged 18-35 received their maiden dose.
Researchers realized that 63 participants who received the placebo and 51 who received the jab got infected with HIV, translating the efficacy to 25.2 per cent.
The women had been offered pre-exposure prophylaxis medication (PrEP) to help avert HIV infection during the clinical trial.
The women who acquired HIV infection were directed to medical care and antiretroviral treatment.
About 40 years since the first cases of AIDS were documented, milestones have been made in HIV treatment changing what was once considered a death sentence into a manageable virus.
The Oral PreP, if taken daily, lowers the infection rate by 99 percent. However, since medical access is unequal across the globe even in rich nations, a vaccine to prevent infection is still prioritized.
Scientists and researchers indicate that HIV is particularly hard to produce a vaccine against since there are hundreds or thousands of variants inside every infected person.
HIV is also classified as a “retrovirus”, meaning it always incorporates itself into its host’s DNA, making it irreversible.