HIV (or human immunodeficiency virus) is what causes AIDS, and is regarded as one of the three biggest diseases to affect individuals in developing countries as well as malaria and tuberculosis.
The World Health Organization (WHO) estimates there are nearly 38 million people living with HIV, of which only 23 million can get ahold of antiretroviral therapies. Of course, this is an increase in the number of people using ARTs since 2016. However, getting treatment for the disease does not mean taking it for granted.
According to South African Medical Research Council President Glenda Gray, the only surefire way to eradicate the disease is through a vaccine, which would be less expensive than intervention. The fact, she said, that there is no vaccine yet means controlling the disease is still a long way away.
There are approximately 1.7 million new infections each year, with 160,000 infections occurring in children under the age of 15.
Gray said milestones are being missed at both local and global levels.
HIV Vaccine Trials Network principal investigator Larry Corey said HIV is the current pandemic that sees 5,000 new infections a day. Corey, and researchers like him, have been working on coming up with an HIV vaccine since the 1980s, but despite the advancements being made, there is still a long way to go.
The majority of vaccines use antibodies that will neutralize viral infections. However, this is not doable with HIV since the virus will reproduce and proliferate so fast that using antibodies is ineffective. On top of that, research shows that HIV has many subtypes. In Europe and North America, people are infected with subtype B HIV, while subtype C is prevalent in eastern and southern Africa.
It can also hide within cells that are free of infection, which suppresses the immune responses in the disease’s early stage. And, according to Gray, it has a genetic diversity more than any known pathogen currently.
Corey, who is a virology expert, said HIV is a complex virus, which masks itself in ways never seen before. The virus, he said, is smart and uses various ways to protect itself, making it more effective than other viruses.
While animal models have been used to look at vaccine effectiveness, it’s often expensive and does not mean a drug will work in humans. Its genetic diversity means it can inflame other infections in the body that the immune system cannot fight against.
Most research has been aimed at understanding the kinds of immune responses and what they must be to eradicate the disease.
The key is to work with antibodies that can recognize and attack the virus before it can infect the whole body. This means focusing on the virus’ weakest areas, so a vaccine has a chance to work.
Corey said there are no human models that show an HIV cure, which establishes there is a barrier in eradicating the disease.
In an important part of dealing with HIV is to come up with a partially-effective vaccine.
Avert, a worldwide sexual health charity, said reducing the number of new infections could be attained by using oral-pre-exposure prophylaxis, antiretroviral treatment and vaccine. According to the organization, an HIV vaccine is much closer today than 10 years ago, which means it is entirely possible to have a vaccine by 2030.
Gray admits that HIV research has received more funding than other infectious diseases, but continued investment may not be as readily available as in the past. She said most vaccine innovations are happening in the public arena while biotechnology and drug companies sit out.
Corey said businesses have steered clear of the practice because it is so risky for them. Corey said U.S. vaccine research investment gets around $700 million from the government with an additional $250 from the Bill & Melinda Gates Foundation. He said it’s the U.S. government and philanthropy that has helped get the HIV research to where it is today with some sense of hope that a vaccine can be developed soon.
Written by Mark Riegel, MD
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