I recently learnt that vaccine basically involves making the body ready by informing it the structure of spike protiens the virus has before hand.
Why are we not able to do this for HIV. What's so differnt about it?
1 Answer
Human Immunodeficiency Virus(HIV) positive means a person has an infection not a disease. Acquired Immunodeficiency Syndrome(AIDS) is caused if infected by HIV. Before we dig into why making a vaccine for HIV is so difficult, let's learn more about what it does to our body so our understanding is better.
The issue is that HIV attack nothing but the immunity providing cells. The cell meditated immunity of a HIV positive human gradually depletes and makes the human prone to multitudes of infections. The human succumbs to these infections and dies, not just because of HIV. The human can be expected to live for about 10 years before a simple or a horrible infection/cancer takes over and kills the human.
Now you might wonder, cancer? How can HIV cause cancer? Yeah, so your immune cells kill cancer cells as well. Cancer is nothing but our own body cells going out of control and causing havoc inside our body. Usually cancer cells are quickly detected by our immune cells and destroyed thus protecting us from cancer. But when HIV causes reduced cell meditated immunity, cancer risks are the highest.
HIV is like the mafia of the most horrible viruses according to me. It can pass through the mother's placenta (which is known to be like the most high level security zone in non-medical terms) during pregnancy.
So with all this, it is pretty clear that HIV is no ordinary virus. It's strong.
So let's get to why it is a difficult task to formulate a vaccine?
- Vaccines mimic immunological response from recovered individuals. And since AIDS patients mostly succumb to death it is an issue to actually formulate a vaccine for such a virus.
- Our immune cells are pretty much blind to it. The mechanism of this smart virus is to hide inside the body of our immune cells and grow a factory that replicates more viral stuff. The virus can have a characteristically long incubation period and hence be toughest to even detect by our immune cells before symptoms suddenly appear.
- Most effective vaccines are whole-killed or live-attenuated organisms; killed HIV-1 does not retain antigenicity and the use of a live retrovirus vaccine raises safety issues.
I used direct references and added some touch of my own to this answer. If anyone wants to read the original+detailed version please see the following: HIV vaccine - Wikipedia
If you are not so used to reading complicated medicine related stuff, I found this article from a reputed source that you can read and comprehend easily and I'm linking it here so that any random visitors to the site with similar questions can understand it too.
