-Decades of HIV Vaccine Research Conclude in PrEPVacc
By Insight Post Uganda
Kampala, Uganda
In a determined quest to finally crack the elusive code of an effective HIV vaccine, Africa is taking the lead in a new trial named PrEPVacc. The trial has emerged as a sign of hope, hailed by some as “the last roll of the dice” for a generation of HIV vaccines.
This trial, currently in its advanced stages, has sparked anticipation and apprehension alike as it tests not just two potential vaccines, but also two forms of pre-exposure prophylaxis (PrEP), aiming to simultaneously evaluate vaccine efficacy and offer protection against HIV transmission.
Driven by African leadership and headquartered in Entebbe, Uganda, with international support, the PrEPVacc trial carries within its potential outcomes the power to herald a new era in vaccine development.
Should success grace its efforts, it could mark the pivotal turning point long awaited by medical science. However, should PrEPVacc falter, it could potentially prompt immunologists to reconsider their strategies for this generation of HIV vaccines.
Nearly four decades have passed since the identification of HIV as the cause of AIDS, and over 36 years since the initiation of the first HIV vaccine trial. Yet, the medical community has been unable to engineer a functional vaccine against this formidable virus.
While antiretroviral treatments are established, their accessibility remains uneven. Disturbingly, according to UNAIDS estimates, approximately 630,000 people succumbed to AIDS-related illnesses globally in 2022, while 39 million people are currently living with HIV, including 1.3 million individuals newly infected in the past year.
The PrEPVacc trial harbours the promise to transcend the limitations that have plagued previous attempts. Notable among these were trials like HVTN 702 (“Uhambo”), halted in February 2020, HVTN 705 (“Imbokodo”), discontinued in 2021, and HVTN 706 (“Mosaico”), terminated in 2023. Though these trials demonstrated safety, they proved ineffective at preventing HIV transmission.
A single glimmer of hope emerged from a clinical trial conducted in Thailand, with findings published in 2009. The RV144 vaccine displayed modest efficacy, approximately 30% effective in preventing HIV infection, though these results remain a subject of debate.
For PrEPVacc to make a substantial impact, either of its two experimental vaccines must achieve an efficacy rate of at least 70%.
Two vaccine candidates under scrutiny employ innovative approaches: one combines synthetic HIV DNA with a protein base, while the other blends DNA, MVA (a weakened pox virus), and a protein base reminiscent of the RV144 vaccine.
According to Jonathan Weber, the lead applicant and PrEPVacc coordinator, the trial represents an evolution of previous efforts rather than a revolution.
Describing the vaccines as “the best we feel, at the moment, that medical science can provide,” Weber anticipates these regimens to be the stepping stones toward progress.
Launched in December 2020, the PrEPVacc trial completed enrollment in March 2023, involving 1,513 participants from South Africa, Uganda, and Tanzania, aged between 18 and 40. While these nations feature high rates of HIV/AIDS, the selection wasn’t solely driven by prevalence.
Eugene Ruzagira, PrEPVacc Trial Director, pointed out that these locations were chosen due to their experience in HIV prevention studies, established community connections, and robust infrastructure.
Despite the funding from the European Union-sponsored EDCTP, the trial’s leadership highlights the necessity for an African-led initiative.
As Ruzagira asserts, “It’s about time.” With decades of groundwork and preparation, the PrEPVacc trial emerges as a defining chapter in the ongoing journey toward finding a powerful and effective HIV vaccine.
Hope For Communities With High HIV Prevalence
In Uganda, the first case of HIV/AIDS was diagnosed in Kyotera district, at the Kasensero landing site in the current Kasensero town council. This significant historical event marked the beginning of an ongoing struggle against the disease.
Ambrose Musasizi, the Kyotera District Communications Officer, expresses a sense of hope ignited by the ongoing trial, considering the profound impact of HIV/AIDS on numerous communities.
According to Musasizi, this optimism is particularly timely, coinciding with the transition of the Rakai Health Sciences Program’s responsibilities to the Infectious Disease Institute, which is yet to start taking charge of HIV services.
The emergence of the devastating HIV/AIDS epidemic in the 1980s initially perplexed communities, often misconstrued as witchcraft due to a lack of awareness. It wasn’t until health experts diagnosed the condition that its true nature was understood.
The disease subsequently spread to encompass the Greater Masaka region, encompassing areas of Masaka, Kyotera, Rakai, Lwengo, Lyantonde, Kalungu, Bukomansimbi, Sembabule, and Kalangala.
This widespread impact led to significant loss of life, triggering a multitude of challenges including the rise of children born with HIV, a surge in orphaned children, the emergence of child-headed households, and deepened poverty within affected communities.
END
English 