Will we ever have a HIV vaccine?

Gary Finnegan

Gary Finnegan

February 23rd, 2021

Gary Finnegan
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‘HIV research boosted COVID-19 vaccine development. Now, the pandemic response could become a catalyst for HIV vaccine breakthroughs’

Crises have a habit of accelerating history, including the pace of technological advancement. The COVID-19 pandemic is no exception. Vaccines were developed, safely but with unprecedented efficiency, less than a year after the WHO declared a global pandemic.

In developing COVID-19 vaccines, researchers were not starting from scratch. They drew on decades of research on coronaviruses (notably SARS and MERS), investment in mRNA vaccine technologies, and the experience of working with regulators and international agencies to combat Ebola and flu outbreaks. Has the role of HIV research been overlooked? 

Key points

  • 30 years of research has yet to deliver a HIV vaccine 
  • HIV vaccine research helped accelerate COVID-19 vaccine development 
  • Success of COVID-19 vaccines could accelerate HIV vaccine development  
  • New technology and political will could provide momentum to the quest for a HIV vaccine 

‘There is no doubt that HIV vaccine research gave COVID-19 vaccine R&D a running start,’ says Mitchell Warren, Executive Director of AVAC, a non-profit organization dedicated to HIV prevention. ‘The three-decades-long quest for a preventive HIV vaccine laid the groundwork for COVID-19 vaccines.’

Investments of more than $15 billion have deepened understanding of viruses, established networks of researchers, built public-private collaborations, and funded clinical trial infrastructure. ‘This expertise was successfully repurposed to develop safe and effective COVID-19 vaccines in record time,’ he told Vaccines Today.  

In addition, Warren points to specific advances in technologies that make it easier to test and visualise viruses, along with techniques for manufacturing vaccines. ‘There has been a lot of acknowledgement of the scientific contributions from HIV to COVID-19 research.’ 

A bumpy road

The question of the hour is why COVID-19 vaccines could be developed in a matter of months, yet there is still no HIV vaccine. The answer, in part, is that HIV has proven to be a particularly challenging adversary.

Like the SARS-CoV-2 virus, HIV is covered in ‘spike’ proteins. If a vaccine could train the immune system to recognise these spikes, it could generate protection through vaccination. To date, this has proven extremely challenging, although details of an early stage trial published this month are cause for cautious optimism. 

Seasoned HIV advocates remain confident that a vaccine could be found, but have grown accustomed to having their hopes dashed. 

‘The road to an HIV vaccine has been very bumpy, there’s no doubt,’ says Warren, pointing to 2009 trials results that buoyed the field but failed to translate into an effective vaccine. In the intervening years, several vaccine candidates have come and gone. Some made it to trials, only to fall short. The latest was a South African trial abandoned in early 2020. 

‘Still, there’s great reason for hope as researchers have learned more and more about the virus and the pathways to prevention through vaccination,’ Warren explains. ‘The field has made tremendous progress despite often being underfunded.’

He has a point. In one frenetic year, the number of COVID-19 vaccines entering advanced clinical trials has eclipsed the number of HIV vaccines reaching the final phase of testing after decades of research. ‘With more resources, HIV vaccine research can capitalise on the advances and changes in vaccine research that have come from COVID-19 vaccine research and move forward to find the vaccines needed to help end HIV,’ according to Warren. 

He says that prior to the pandemic, there was already a lot of excitement around new approaches to HIV vaccine research. ‘There will no doubt be technology and techniques from COVID-19 research, including mRNA, that will benefit HIV vaccine research,’ according to Warren. ‘Moderna has announced a new partnership to apply their mRNA technology to an HIV vaccine candidate. And a HIV vaccine being studied in two efficacy trials is the Janssen/Johnson and Johnson Adeno26-based candidate, which was quickly adapted for a COVID vaccine.’

Political will

Along with harnessing new technologies, the key ingredient for HIV breakthroughs would be investment of scientific energy and political capital. ‘The single biggest benefit to HIV vaccine research would be a transfer of the political will and adequate funding to supercharge vaccine development for HIV,’  says Warren. ‘We’ve learned from COVID-19 that unprecedented funding and cooperation among governments, industry and research groups can speed development of new technologies. We need to apply these lessons to HIV.’ 

With the right combination of supports, a HIV vaccine could become a valuable tool for controlling a disease which has become increasingly manageable through antiretroviral therapies and medication that reduces the spread of disease. ‘I believe an HIV vaccine is possible and will be developed, but I don’t know what the time frame is, especially given the hit that HIV vaccine research has taken with so much attention and resources turned to COVID-19,’ Warren says.  

Human trial tests new approach to HIV vaccine

‘HIV isn’t really one virus. It’s more like 50 million different viruses,’ says Dr William Schief, a HIV vaccines researcher at Scripps Research. ‘Antibodies against one HIV spike will not block another HIV spike.’

Schief’s team of researchers at the IAVI Neutralizing Antibody Center is working on a promising new vaccine that would stimulate the body to make immune cells capable of protecting against the fast-moving HIV virus.

Results from an early clinical trial look promising, according to scientists at IAVI and Scripps Research. It is seen as a potential first step in finding a vaccine that blocks all kinds of HIV.

‘This is a tremendous achievement for vaccine science as a whole,’ says Dr Dennis Burton, director of the NIH Consortium for HIV/AIDS Vaccine Development. ‘This clinical trial has shown that we can drive immune responses in predictable ways to make new and better vaccines, and not just for HIV. We believe this type of vaccine engineering can be applied more broadly, bringing about a new day in vaccinology.’