Top 5 HIV cure and vaccine stories from CROI 2020

Ravindra Gupta first presenting the case at CROI 2019 in Seattle. Photo by Liz Highleyman.

HIV researchers present some of the most important and cutting-edge studies each year at the Conference on Retroviruses and Opportunistic Infections (CROI). This year the face-to-face meeting was cancelled at the last minute and a virtual conference was held instead.

This did not stop some important news on HIV cure and vaccine from being presented:

The London man who appears to have been cured of HIV after 30 months without antiretroviral therapy has been named as Adam Castillejo. He had had a bone marrow transplant from a donor with a rare genetic profile as part of a gruelling treatment for cancer. Researchers are still unable to find functional HIV in his blood, semen, lymph nodes, gut tissue or cerebrospinal fluid.

Glossary

CD4 cells

The primary white blood cells of the immune system, which signal to other immune system cells how and when to fight infections. HIV preferentially infects and destroys CD4 cells, which are also known as CD4+ T cells or T helper cells.

cure

To eliminate a disease or a condition in an individual, or to fully restore health. A cure for HIV infection is one of the ultimate long-term goals of research today. It refers to a strategy or strategies that would eliminate HIV from a person’s body, or permanently control the virus and render it unable to cause disease. A ‘sterilising’ cure would completely eliminate the virus. A ‘functional’ cure would suppress HIV viral load, keeping it below the level of detection without the use of ART. The virus would not be eliminated from the body but would be effectively controlled and prevented from causing any illness. 

neutralising antibody

An antibody that neutralises (renders harmless) an infectious microorganism.

broadly neutralising antibodies (bNAbs)

A neutralising antibody (NAb) is an antibody that fully defends its target cell from an antigen. A broadly neutralising antibody (bNAb) is a neutralising antibody that has this effect against a wide range of antigens. A number of broadly neutralising antibodies have been isolated from persons living with HIV. Some of them are being studied and, in some cases, used in clinical trials, to defend humans against HIV infection, treat HIV infection, and kill HIV-infected CD4+ T cells in latent reservoirs.

bone marrow

Cells in the middle of bones which are responsible for producing blood cells.

A four-year-old child who acquired HIV during gestation, started antiretroviral therapy within two days after birth and stopped a year later has now been in sustained remission for three years after stopping treatment.

Scientists have for the first time produced a vaccine that induced human cells to generate broadly neutralising antibodies to HIV. This may be an important step forwards towards a vaccine that could work both for HIV prevention and HIV treatment.

A symposium held before the main conference outlined the progress being made in two different approaches to curing HIV. One is to use a combination of therapies to purge the majority of HIV-infected cells from the body and suppress the rest. The other is using novel genetic-engineering techniques either to make CD4 cells that are immune to HIV, or CD4 cells that display novel, hypersensitive immune reactions to the virus.

Given immunological differences between women and men, sex is likely to be a crucial factor affecting the success of HIV cure strategies. However, enrolment of women in clinical trials and basic research studies has been limited.

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