The vaccine against the HIV virus is in the study phase, being researched by scientists around the world, but there is still no vaccine that is truly effective. Over the years there have been many hypotheses that the ideal vaccine would have been found, however, the vast majority did not manage to pass the second phase of vaccine testing and was not made available to the population.
HIV is a complex virus that acts directly on the main cell of the immune system, causing changes in the immune response and making it more difficult to combat. Find out more about HIV.
Because HIV still doesn’t have a vaccine
There is currently no effective vaccine against the HIV virus, because it behaves differently from other viruses, such as the flu or chickenpox, for example. In the case of HIV, the virus affects one of the body’s most important defense cells, the CD4 T lymphocyte, which controls the entire body’s immune response. ‘Normal’ vaccines offer a part of the live or dead virus, which is enough to make the body recognize the offending agent and stimulate the production of antibodies against that virus.
However, in the case of HIV, it is not enough to just stimulate the production of antibodies, as this is not enough for the body to fight the disease. HIV-positive people have many antibodies circulating in their body, however these antibodies are not capable of eliminating the HIV virus. Therefore, the HIV vaccine should work differently from other types of existing vaccines against the most common viruses.
What makes it difficult to create an HIV vaccine
One of the factors that makes it difficult to create an HIV vaccine is the fact that the virus attacks the cell responsible for regulating the immune system, the CD4 T lymphocyte, which causes uncontrolled production of antibodies. Furthermore, the HIV virus can undergo several modifications and may have different characteristics between people. Thus, even if a vaccine for the HIV virus is discovered, another person may be a carrier of the modified virus, for example, and thus the vaccine will have no effect.
Another factor that makes studies difficult is that the HIV virus is not aggressive in animals, and therefore, tests can only be carried out on monkeys (because they have DNA very similar to humans) or on humans themselves. Research with monkeys is very expensive and there are very strict rules to protect the animals, which make this research not always viable, and in humans there is not much research that has passed the 2nd phase of studies, which corresponds to the phase in which the vaccine is administered to a larger number of people.
Find out more about the vaccine testing phases.
Furthermore, several types of HIV with different characteristics have been identified, mainly related to the proteins that constitute it. Therefore, due to diversity, manufacturing a universal vaccine is difficult, as the vaccine that may work for one type of HIV may not be as effective for another.
