Imperial College London

The search for an HIV vaccine: Professor Jonathan Weber reflects on his career


From its emergence in the 1980s to setting up multi-national vaccine trials, Prof Jonathan Weber reflects on his career spent researching HIV/AIDS.

Professor Jonathan Weber, Dean of the Faculty of Medicine at Imperial College London, has been involved in HIV research from the very beginning, with a career spanning almost 40 years from the first discovery of the virus in 1981.

As a Fellow of the Academy of Medical Sciences, he was invited to speak on his career in HIV at AMSlives 2020 in January. The event hosted by award-winning science journalist, Linda Geddes, featured five short talks suitable for a lay audience. Professor Deborah Ashby, Director of Imperial’s School of Public Health was also one of the speakers.

‘Extraordinary scientific response’

In his talk he reflects on the reaction of the medical community to the AIDS epidemic and the evolution of treatments that enable someone newly diagnosed with HIV in the UK today to expect to live a normal life.

“The scientific response to the HIV epidemic was completely extraordinary: HIV the causative virus was isolated and the sequence characterized by 1984; the first drug became available by 1987 and then with engagement of the pharmaceutical industry, who made a suite of new drugs throughout the early 1990s.

“After a series of pivotal clinical trials—many conducted here in London and by the Medical Research Council—they showed that combinations of these antiretroviral drugs could completely suppress viral replication in infected individuals; so much so that anyone newly infected by HIV today starting on these combination drugs will live a normal healthy life and can expect a normal life expectancy—an extraordinary achievement.”

Working to end the transmission

Despite treatment advancements, Professor Weber highlights that there is still work to do on controlling the transmission of HIV. He emphasises that to truly control the disease, we always need a safe and effective HIV vaccine:

“Despite these fantastic advances and these wonderful drugs we've not got on top of the transmission of HIV. To give you an example, last year in London, ten young gay men became newly HIV infected every single day. I absolutely believe—just like the control of infectious diseases—this is best achieved by a safe and effective vaccine.”

So why don't we have a vaccine against HIV?

Professor Jonathan Weber explains that there are three challenges we have to be overcome to progress with a vaccine:

“First, there's no natural immunity to HIV—no-one pushes the virus off. Second, there's no animal model for HIV—no other animals get the disease in quite the same way that people do. And thirdly, the virus is highly variable, presenting an ever-moving target for vaccine development.” 

Professor Weber with colleagues at a University of Zambia clinical trials site at Mazabuka in 2006
Professor Weber with colleagues at a University of Zambia clinical trials site at Mazabuka in 2006

Professor Weber has been at the forefront of efforts to develop an HIV vaccine since 1999 when he founded a cross-European consortium. His work today is looking at using vaccines in combination, priming with one and then boosting with another (prime-boost technique). This technique is now being tested in a PrEPVacc trial starting in Uganda, Tanzania, Mozambique and South Africa later this year.

Find out more about the trial, including how to take part



Ellyw Evans

Ellyw Evans
Faculty of Medicine Centre

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