The world has survived too many pandemics throughout history. Each one of them has hit humanity very hard and taken so many lives before we learned how to control them. Science has developed so many treatments against most of these like vaccines and prevention treatments; but still, with all of that in mind, there is especially this one disease that exceeds our knowledge on how to prevent it.
What is HIV/AIDS and why is it hard to create a vaccine for it?
The Human Immunodeficiency Virus or Acquired Immunodeficiency Syndrome is a disease that was discovered in 1983 and can be transmitted through blood or body fluids like blood transfusion, organ transplants, sexual intercourse, pregnancy, etc. Unfortunately, the HIV infection cannot be cured yet and when it is in its late stages, that’s when it is called AIDS.
According to the World Health Organization, once acquired, the virus attacks directly the immune system and weakens the person’s ability to successfully fight infections like others can. Because of this, it is very hard to create a vaccine that could prevent people from getting infected. Usually, these are meant to prepare the immune system for when the virus gets in the body so that it then attacks it, but when the pathogen is constantly mutating even when already inside the human body, then it makes it so hard to create a definite vaccine for it.
First Predictions
Since its discovery, the desperate need for creating a vaccine against HIV/AIDS has been so strong that in 1984 the US Secretary of Health and Human Services of that time made a very positive declaration regarding the development of this vaccine.
She expected that in about 2 years time, scientists would have found a solution to that need and they could start testing it on humans; something that didn’t happen due to two main reasons: the first one being the fact that vaccines normally take at least 10 years to be securely developed and approved for human application, and the second one being the complexity of the virus itself that changes continuously from case to case
Why wasn’t it possible in the first place?
Up to this day, no one has managed to naturally recover from this infection. Usually, when you fight a virus like the flu or chickenpox and manage to recover from it, you naturally develop antibodies that will help you deal with future infections, but with HIV, that doesn’t work like that.
When a person gets infected, their immune system gets completely destroyed especially when it gets to be considered AIDS. Along with that, the virus keeps mutating inside the body so it is basically impossible that the person generates the needed antibodies to test them and try to create a vaccine out of them.
The biggest attempt
In 2009, the results for the largest HIV vaccine trial in history were announced. The main focus of this test was to combine the application of two types of vaccines. One that would stimulate the immune response of the T cells, which are the main ones destroyed by this virus; and the other one that would work as a booster while stimulating the immune responses of antibodies.
Around 16,000 people participated in this test and only 31% of them showed positive results, which was not enough in order to be approved for the official application.
Present Day
Even though this last test could not be approved, the percentage of success that it got helped future scientists to take this process as a base for future investigations.
They are still experimenting with the use of a viral vector (a modified virus that helps introduce this new genetic material to the cell nucleus) that works as a preventive vaccine and could also have therapeutic applications but this process is still being tested in preclinical studies.
Photos from Pexels
