Towards an AIDS vaccine, once more

There is some hopeful news that an AIDS vaccine might be possible.

There have been multiple trials with AIDS vaccines in the past, all of which have failed, but now for the first time there is some clinical data that shows that infection rates were in fact lowered by the vaccination. Only by a third, though, so there is still a long way to go, but it is a step in the right direction.

Why, you ask, is an AIDS vaccine so hard to develop?

The reason is that almost all vaccines work on diseases that the human body can successfully fight on its own, mostly. Take for example smallpox, where about two thirds of the infected did recover from it before vaccines against it were developed. So all the vaccine needs to do is to prepare and boost the immune response ahead of time. This is how most vaccines work.

Chronic diseases on the other hand have managed to develop strategies to outsmart the human immune system. No matter how hard the immune system tries, for the vast majority of people the immune system can not clear the infection. So simply boosting and preparing the immune system through a vaccine does not work here, since there is no adequate immune response in the first place.

This is the reason why for this AIDS vaccine a different strategy was used. The vaccination consists of two vaccines, each of which works through a different mechanism. One of the two had been tested before and was found to not work well enough on its own.

The downside of this study is that the vaccines did specifically target HIV strains circulating in Thailand, where the study was performed, and even then only partial protection was achieved.

So maybe as for the AIDS drugs, the way forward for an AIDS vaccine is to have cocktails of different vaccines that complement each other.

If (big if) these initial results hold up.