Are we getting closer to a HIV vaccine?

In the wake of the infected blood scandal, where more than 30,000 people were infected with HIV and hepatitis C from 1970 to 1991 by contaminated blood products and transfusions, the United Kingdom has published a public inquiry report.

It has drawn the world’s attention once again to the HIV pandemic, which has claimed millions of lives globally - disproportionately in Africa.

For decades, the relentless pursuit by the global scientific community of a HIV vaccine has featured a cycle of breakthroughs, hope and setbacks. Yet, recent advancements that can target multiple strains of HIV by broadly neutralising antibodies (bNAbs) offer renewed optimism.

How close are we really to achieving an effective vaccine?

Why is finding a vaccine important

Finding a HIV vaccine is crucial because it represents the most promising strategy for halting the spread of the virus and ultimately eradicating it. In Africa, where HIV/Aids has had a devastating impact, the significance of a vaccine cannot be overstated. Sub-Saharan Africa is home to nearly 70 per cent of the global HIV-positive population, with millions of new infections each year. The socio-economic burden of the epidemic is immense, affecting families, communities and entire nations. An effective HIV vaccine would dramatically reduce new infections, improve public health and alleviate the long-term healthcare costs associated with managing the disease. Moreover, it would empower individuals and communities, fostering economic stability and enabling a brighter future for the continent. In essence, a HIV vaccine is not just a medical breakthrough; it is a lifeline for Africa's development and well-being.

The hope of broadly neutralising antibodies

Broadly neutralising antibodies are like elite soldiers in our immune system, capable of recognising and neutralising various strains of HIV. Recently, scientists have demonstrated that it is possible to induce these crucial antibodies through vaccination. This breakthrough provides significant hope that we might finally be on the right path toward developing an effective HIV vaccine.

Learning from past failures

Antiretroviral therapy (ART) has been a lifesaver, transforming HIV from a death sentence to a manageable condition. However, ART is not a cure, and a vaccine remains the ultimate goal to end the epidemic once and for all.

The journey has been anything but smooth. Several high-profile HIV vaccine trials over the years have failed, dampening hopes and fuelling skepticism that an effective vaccine will ever be developed for AIDS. Despite setbacks in the development of a vaccine, its importance cannot be overstated, especially for regions like Sub-Saharan Africa, where HIV remains a pervasive and devastating epidemic.

A new approach: Small-scale trials

A promising strategy has been to conduct multiple small-scale, proof-of-concept clinical trials, allowing researchers to test multiple vaccine approaches on a smaller scale. This enables a thorough assessment of safety and efficacy before investing time and money into larger, more expensive trials. This iterative process helps refine vaccine candidates and increases the chance of success of large-scale trials.

Several novel HIV vaccine concepts are currently undergoing small-scale clinical trials being held worldwide, including in Africa. For example, collaborations among the International AIDS Vaccine Initiative, Scripps Research Institute and Moderna include the first-in-Africa clinical trial of an mRNA HIV vaccine. These trials allow for iterative improvements, increasing the likelihood that when and if it moves to a large-scale trial, it will result in a successful vaccine.

The road ahead

Progress made so far is encouraging. The scientific community is cautiously optimistic that with continued research, innovation and collaboration, a HIV vaccine is within reach. The small-scale trials currently underway are paving the way for future large-scale trials that could finally bring an effective HIV vaccine to fruition.

The devastation of Aids started to come to public consciousness more than 40 years ago. In the intervening time, there has been a relentless drive to develop a HIV vaccine to prevent the disease. Although the road has and continues to be long and challenging, recent advancements in inducing broadly neutralising antibodies and the strategic implementation of small-scale clinical trials provide hope.

Mr Chopera is a medical virologist and a programme manager for the Leadership for African Research Networks at the Science for Africa Foundation