Researchers Unveil A Potential HIV Vaccine

A step toward developing a novel type of vaccine regimen believed to be protective against HIV is one of the  researchers' accomplished mission

Researchers Unveil A Potential HIV Vaccine
Photo courtesy

Recently, researchers have been overworking to find solutions and especially vaccines to the worlds’ most threatening diseases, covid-19 and HIV/ AIDS.

A step toward developing a novel type of vaccine regimen believed to be protective against HIV is one of the  researchers' accomplished mission.

The virus, which progressively weakens the immune system, has affected about 38 million people worldwide, according to a Trusted Source.

Highly effective antiviral treatments for HIV are however available, but those living with the virus are advised to take the drugs for the rest of their life while the long-term health effects of infection remain challenging.

The World Health Organization (WHO)Trusted Source estimates that, as a result of limited access to prevention and treatment services in some parts of the world, there were 1.7 million new infections with HIV in 2019, and 690,000 people died from HIV-related causes.

Since the onset of the virus, scientists have failed to develop an effective vaccine because most of the surface of the virus is densely coated with sugar molecules that do not trigger an immune response, and the parts that are exposed are highly variable.

HIV uses spike proteins on its outer surface to gain entry to its host cells.

William Schief, Ph.D., a professor and immunologist at the Scripps Research Institute in La Jolla, CA, and executive director of the International AIDS Vaccine Initiative (IAVI) explains: “The spike protein on HIV viruses is much more devious.”

As a result of the rapid mutation of the genes that make the spike, HIV has millions of different strains; Due to this, antibodies against one strain are unlikely to neutralize the others, he said.

“And so HIV is not really one virus,” added Prof. Schief. “It’s really like 50 million different viruses around the world right now.”

Researchers have, however, known for a long time that there are hard-to-access parts of the spike and that do not change very much.

Antibodies that bind to such regions, known as broadly neutralizing antibodies (bnAbs) because, in theory, they could target a wide variety of HIV strains.

According to the scientists, people with HIV make these antibodies naturally thus giving the scientists an opportunity to identify where the antibodies bind to the virus; With this knowledge, they can develop “immunogens” to use in vaccines.

“The catch is that only a rare type of immature immune cell, known as a naive B cell, can develop into circulating B cells capable of making bnAbs against HIV,” says Prof. Schief, “and only about 1 in a million naive B cells have this potential.”

In order to overcome this issue, he and his colleagues at Scripps Research and IAVI applied a technique called germline targeting to create a vaccine that activates the rare cells.

In the first phase of clinical trial, the vaccine appeared to be safe, and it had the desired effect in nearly all of the volunteers who received it.

Researchers at George Washington University in Washington, D.C., and the Fred Hutchinson Cancer Research Center in Seattle, WA, had recruited 48 healthy adult volunteers for the trial.

The participants were given two doses of either the vaccine or a placebo.

In reference to the scientists' report, the vaccine activated naive B cells in 97% of participants who received it.

“A holy grail of the HIV vaccine field is to elicit broadly neutralizing antibodies by vaccination. And here, we’ve shown in humans that we can start that process,” says Prof. Schief.

Prof. Schief. presented the results at a virtual conference of the International AIDS Society HIV Research for Prevention on February 3, 2021.

Even though the trial was small, it is important to note that further research and several more clinical trials will be necessary to develop and test later stages in the vaccine regimen, he said.

This would be the first vaccine in a series of injections to create immunity against the virus.

Basing on the findings, The first jab would “wake up” the naive B cells, and subsequent jabs would train their descendants to produce bnAbs against HIV.

“We believe this approach will be key to making an HIV vaccine and possibly important for making vaccines against other pathogens,” said Prof. Schief in a press release from Scripps.

Prof. Schief believes that researchers could use the same approach to develop vaccines against other challenging pathogens, such as hepatitis C, influenza, Zika, dengue and malaria.

The team, has since joined forces with the biotech company Moderna to develop an mRNA-based vaccine that targets the same cells.

As it has with the development of COVID-19 vaccines, mRNA technology is expected to accelerate the process of developing the vaccines.