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Today is annual World AIDS Day: an opportunity for people worldwide to unite in the fight against HIV, show their support for people living with HIV and to commemorate people who have died. We spoke to one of the Heads of our Infectious Diseases Faculty, Dr. Robert C. Gallo, who became world famous in 1984 for the co-discovery of HIV as the cause of AIDS and pioneered the development of a rapid HIV blood test.

You played a key role in the discovery of the human immunodeficiency virus (HIV) as the infectious agent responsible for acquired immune deficiency syndrome (AIDS) and in the development of the HIV blood test. Can you tell us a little about that time and how you came about that discovery?

Statistic: AIDS.gov

It was an exciting but very stressful time. Exciting because new discoveries were coming rapidly and we were steadily gaining evidence that indeed this retrovirus was the cause of AIDS which previously had seemingly been a mysterious illness of sudden onset. Yet, it was also a time of stress: the pressure to find the next result; the pressure to get a workable, accurate and available blood test for the world; to convince people that HIV is the cause of AIDS and to diminish the rumours which were so rife of its origin. We also felt great pressure to make the public understand that the people infected were not readily able to infect other people through social contact, pressure of the politics and debates over the patent rights for the blood test, and – above all – the pressure to develop a much needed therapy for HIV infected people.

You published your first articles on HIV in 1984. More recently, there have been several studies that demonstrate potential for an HIV vaccine. How close do you think we are to this?

The answer to that question is fraught with difficulties and requires almost a chapter rather than a few sentences. To date, there is no effective, preventive HIV vaccine. On the other hand, the science has been truly amazing and gave us insights into immune mechanisms and the difficulties of a vaccine against a retrovirus, the likes of which we had not seen in the history of vaccine research.

Among others, we have a candidate vaccine for HIV prevention. It is in Phase I trials now and will soon enter Phase II. Do I think it will work? There is one other vaccine that had some very minimal efficacy. It was developed by the U.S. Army in collaboration with workers in Thailand.  Overall, it gave protection that only approached 30% or maybe even less. The trial was called RV144. Our own vaccine gives a similar immune response when tested in monkeys, but, as with all vaccine candidates that target the envelope protein gp120, the generated antibodies are not long-lasting. This also seemed to be the key problem in the RV144 trial: the antibodies did not last. I have no reason to believe that our vaccine candidate won’t face the same problems.

HIV budding out of a human immune cell (EM Image: NIH)

We believe that until the problem of longevity of antibodies is solved, the vaccine will only marginally work. Our hope is to understand why the antibodies don’t last, and how, so we can fix it. That is where I see the field from our perspective from the Institute of Human Virology at the University of Maryland School of Medicine in Baltimore, Maryland. A vaccine against a retrovirus must be long-lasting because there is no time for the immune system to be recalled when a person gets infected. The immune system must stay ready all the time, because a retroviral infection is associated with rapid integration (within a day) of its genes into the host chromosomal DNA and within a few days newly produced virus particles will be released. Therefore, generating a successful vaccine against a retrovirus is far more difficult than the conventional vaccines against acute virus infections as they do not require a rapid response from the immune system.

This year’s World AIDS Day motto is “HIV Stigma: Not retro, just wrong”. The first world AIDS Day took place on December 1^st 1988, dedicated to raising awareness of the AIDS pandemic. Almost 30 years later, there is still a stigma around AIDS and HIV. Why do you think that is and what can be done to change that?

I don’t know why there is still such a stigma. I suppose it is because there are so many psycho-sexual aspects to HIV infection that somehow don’t come up with a lot of other sexually transmitted infections. It tends to breed a lot of fears that are not justifiable. I don’t know how to change these perceptions except to be aware of them and educate people as much as we can. Frankly, I think the stigma has tremendously improved since the 1980’s, and I expect it will further improve.

The AIDS Memorial Quilt is shown for the first time on the Mall in Washington DC., in October 1987. (Photo: Lee Snider/Corbis)

To check your understanding of HIV and AIDS, visit https://www.nat.org.uk/we-inform/do-i-understand-hiv.