Today, there is a treatment that allows HIV-negative people to remain HIV even if they have an HIV partner. However, to defeat the AIDS-causing virus, doctors must come up with a vaccine.
Decades have led to dashed hopes, but it could be a vaccine is right around the corner.
A wide-scale clinical trial will launch in the fall with many others already going on, but scientists are a bit pessimistic and optimistic that they may have a way to fight HIV before a person is exposed to it.
HIV Vaccine Trials Lead Investigator Dr. Larry Corey said a disease that can be transmitted with no symptoms means someone would get it when they don’t expect to. This, he said, is why the best measure of control is a vaccine.
Public health experts and scientists are in agreement that the best way to eradicate a disease is to use a vaccine. It’s worked for diseases such as polio, smallpox, etc. And, if pre-exposure prophylaxis and antiretroviral therapy are combined, it may work for HIV as well.
With a vaccine, it could spell the end of AIDS altogether!
There are over 37 million people who have HIV, and another 5,000 a day unknowingly are infected with it. There are also roughly 180,000 newborns who get the disease.
It would seem the virus is doing quite well.
HIV (human immunodeficiency virus) goes after the body’s white blood cells, which the body uses to fight off infections. If not treated, the white blood cells count drops to critical levels and causes AIDS. When a person has AIDS, they are susceptible to a host of fungi and bacteria that can lead to meningitis, tuberculosis and other types of very serious diseases.
When Gallo and other researchers discovered HIV was the cause behind AIDS in 1984, it wasn’t long before they knew there had to be a way for people to be inoculated from the virus. Back then, it seems, researchers were already working on the way to develop a vaccine.
A vaccine would ready the immune system for HIV by introducing a weakened or dead version of it. Should the real threat occur, the body already has the tools to fight it. HIV is not the same as other vaccinated-threats such as polio or measles, in that no person has ever been able to fight off the virus without some type of intervention.
Therefore, scientists looking to create a vaccine must create one out of thin air with no cheat sheet. And, if scientists are successful in developing the vaccine, it must work much harder to attain the end result.
This means scientists must be shrewder than the virus itself, which means understanding the connection between the immune system and pathogen that scientists have yet to identify.
The problem with HIV is that there are too many genetic complications. For example, it has more genetic diversity than other known viruses. It will constantly replicate itself and make mistakes while doing so and does nothing to correct them. Since it can mutate so easily, there’s no easy to come up with a vaccine.
And, each part of the world has its own HIV subtype. In both Europe and North America, there is subtype B while eastern and southern Africa is known to carry subtype C. For a vaccine to be considered effective, it must use the myriad of HIV variants to ensure it works for all the different types.
There is too much variability, but protection must be for all of it.
This plan is going to be attempted come this fall in the Mosaico trial. Johnson & Johnson developed an experimental vaccine that is comprised of an array of HIV strains.
In its preclinical trials, 66 percent of non-human primates were vaccinated and protected against HIV-like viruses. Additional studies in humans paved the way for the final make-up. Scientists will be enrolling 3,800 healthy people at over 50 trial sites across Europe, North and South America, coming from groups that are deemed to be at high risk for getting HIV. They will receive four vaccinations in a year’s time.
It’s a double-blind study, which means researches and participants do not know who gets the experimental vaccine and who gets the placebo. If researchers discover the vaccine is successful, they hope it can be used worldwide.
Scientists are getting excited about the prospect!
Included in the study enrollment process, researchers will take to volunteers about the advantages PrEP has for them and encourage them to use the drug before partaking in the study. People who say they want to forgo the treatment can still be eligible.
There are other vaccine-related trials going on currently. For example, in sub-Saharan Africa, 2,600 women are being tested, but the results will not be available until 2021. The testing began in 2017.Other similar trials are taking place in North America, South America and South Africa.
Scientists understand that not all vaccines are foolproof, but International AIDS Vaccine Initiative researchers say a 70 percent effective vaccine would be better than nothing and could help prevent new infections than the current-relied-upon PrEP.
Researchers are hoping the Mosaico trial will have a 65 percent effectiveness rate.
Written by Mark Riegel, MD
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