HIV Vaccine: Special Antibodies That Neutralize Virus Could Hold the Key

Scientists are one step closer to creating an HIV vaccine thanks to a study uncovering how some human bodies attack the virus.

A team of scientists in Switzerland investigated the potential uses of special antibodies created by a minority of people who are infected with HIV-1, the most common form of HIV. These antibodies are special because they don't just attack one but almost all strains of the virus.

Researchers at the University of Zurich and University Hospital Zurich have already spent years trying to answer why some people create these antibodies in the hope of developing an HIV vaccine.

They previously identified potential factors including the amount of HIV in a person's blood, the diversity of the strains of the viruses, the length of time a person is infected, and how a patient's ethnicity could affect their immune system.

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Huldrych Günthard, deputy director of the Department of Infectious Diseases and Hospital Epidemiology at University Hospital Zurich, said in a statement: "In our new study, we were able to identify another factor: The genome of the HIV virus."

Data and blood samples from around 4,500 people infected with HIV who took part in the Swiss HIV Cohort Study and the Zurich Primary HIV Infection studies formed the basis of the investigation.

The researchers identified 303 patients who were likely infected by the same strain of the virus. These are known as transmission pairs, where the viruses' genomic RNA (which helps genes express themselves) are similar.

Dr. Roger Kouyos, research group leader at the Department of Infectious Diseases and Hospital Epidemiology at University Hospital Zurich, explained in a statement: "By comparing the immune response of these pairs of patients, we were able to show that the HI virus [HIV] itself has an influence on the extent and specificity of the antibody reactions."

Antibodies attack HIV by binding to proteins on the surface of the virus called viral envelopes. Different strains and subtypes of viruses have different envelopes. The researchers honed in on transmission pairs whose antibodies were powerful.

Scientists have investigated how special antibodies could lead to a HIV vaccine. Getty Images

Dr. Alexandra Trkola, virologist and head of the Institute of Medical Virology at University Hospital Zurich, said: "We discovered that there must be a special envelope protein that causes an efficient defense."

The next step is to put these findings to use to create an HIV vaccine. Before that can happen, scientists must identify the envelope proteins and virus strains which cause these broadly acting antibodies to form.

Trkola said: "We have found one candidate. Based on that, we now want to begin developing an immunogen ourselves."

She told Newsweek there is "still a long way to go" before a HIV vaccine is rolled out.

The research was published in the journal Nature. It follows a study conducted at Harvard Medical School showing a jab could trigger immune responses against HIV, and protect monkeys from the virus.

Dr. Dan Barouch, professor of Medicine at Harvard Medical School and author of the study, told Newsweek at the time the study was published in The Lancet he was "cautiously optimistic" about the results. However, he emphasized there are many obstacles to overcome before a vaccine is rolled out for humans.

This article has been updated with comment from Alexandra Trkola.