The search for an HIV vaccine has been ongoing for four decades, but the recent news that Janssen Pharmaceuticals, a division of Johnson & Johnson, has discontinued the only current late-stage clinical trial of a vaccine due to it being ineffective has caused a setback in this effort. Mitchell Warren, executive director of AVAC, an organization that advocates for HIV prevention to end AIDS, expressed disappointment in the outcome.

Despite this setback, several early, small-scale clinical trials are underway, and more may enter the research pipeline in the future. Since 1982, when the U.S. Centers for Disease Control first named the syndrome "AIDS," years of fear and death gave way to scientific advancements in understanding and treating AIDS. However, the ultimate goal has always been finding a vaccine to prevent people from being infected with HIV.

Dr. Susan Buchbinder, director of HIV prevention research at the San Francisco Department of Public Health and a professor at the University of California, San Francisco, pointed out that the only way to eradicate a human disease is with a vaccine, and smallpox is an example of this.

Developing HIV Vaccine

Medical progress has been made in treating AIDS through the use of antiretroviral medications (ART) to suppress the virus and keep the disease under control, as well as pre-exposure prophylaxis (PrEP) drugs to prevent HIV transmission if taken correctly by uninfected individuals who see themselves at risk. However, while almost 29 million of the world's 38 million HIV-infected people have access to life-saving ART drugs, access to PrEP medications has been slow, with 97% of the 940,000 worldwide PrEP users living in just 30 countries.

Additionally, a vaccine to prevent HIV is still not yet available, despite the rapid development of COVID-19 vaccines that prevent severe disease, hospitalization, and death in most cases. The question is raised, if scientists were able to develop a vaccine so quickly for COVID-19, why is a vaccine to prevent HIV not yet available? The development of a vaccine to prevent HIV has proven to be challenging due to the rate at which the virus mutates. According to Mitchell Warren, executive director of AVAC, the AIDS virus mutates much more rapidly than COVID-19, making it difficult to create a vaccine that can effectively target it.

The variability of HIV in one person's body can result in more variants within days after infection than all the variants of COVID. This means that as a vaccine is being developed to attack HIV, the virus may already be mutating out of its reach. The main role of a vaccine is to educate the immune system to recognize the disease and create antibodies to fight it off, but so far, this has not been successful with HIV. Unlike COVID-19, the AIDS virus mutates very quickly and is a moving target for the immune system, making it difficult to create a vaccine that can effectively recognize and fight off the disease.

A nurse enrolls a participant in an HIV vaccine trial in Masaka, Uganda, an African-led project.
(Photo: Luke Dray/Getty Images)
A nurse enrols a participant in an HIV vaccine trial in Masaka, Uganda, an African-led project.

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Failure of HIV Vaccine Development

Another factor that has hindered progress is that the body's immune system does not naturally clear HIV, unlike COVID-19. While ART and PrEP medications can suppress the virus and prevent transmission, a vaccine that can prevent infection has yet to be developed. While antiretroviral medications (ART) and pre-exposure prophylaxis (PrEP) have helped to suppress the virus and prevent transmission of HIV, access to these medications is not equal globally, and not everyone can adhere to the required regimen. Additionally, the virus mutates, making it difficult to develop a vaccine.

A vaccine would provide a more effective and sustainable solution to preventing the spread of HIV, especially in parts of the world where access to ART and PrEP is limited. Therefore, the search for an HIV vaccine continues to be important in the effort to end the AIDS epidemic. Despite the challenges, scientists and researchers continue to work towards finding a vaccine for HIV/AIDS. The failure of the Johnson & Johnson HIV vaccine was a setback, but it has not dampened the optimism of those working in the field.

There are ongoing trials of various experimental HIV vaccines using new technologies such as messenger RNA (mRNA), which was used in developing the Pfizer and Moderna COVID-19 vaccines. The HIV Vaccine Trials Network, an international collaboration dedicated to the evaluation of vaccines to prevent the transmission of HIV, has a variety of trials underway. While it is still early, and the results are yet to be determined, researchers have learned much from each trial. It's a long road ahead, but there is hope that a vaccine will be developed to prevent the spread of HIV/AIDS.

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