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From NPR interviews I listened to during the early days of the mRNA vaccines showing incredible promise, I understood that one of the problems with HIV is that

From NPR interviews I listened to during the early days of the mRNA vaccines showing incredible promise, I understood that one of the problems with HIV is that the human body does not naturally have strong defense mechanisms (antibodies, etc) for this type of virus. Hence, the usual vaccine path (or mRNA derived method) of accelerating the learning of the body's T-cells, etc. to manufacture its own defenses is not very effective -- they are not there to begin with. Is that not correct? What are they doing differently here?

est31 6y ago
Passive immunization with broadly neutralizing antibodies have been shown to prevent HIV infection in various animal studies. The goal is apparently to make the immune system able to manufacture such antibodies. The human immune system is fundamentally able to come up with these antibodies on its own, as some HIV positive individuals do develop them, but at least during natural infection they don't appear in everyone. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4604566/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4604566/ However, antibody levels won't be as high in vaccinated individuals as they are in those passive immunization animal studies, at least not forever. The body can't afford to produce full levels of antibodies for all antigens all the time. Instead, human bodies reduce produced antibody levels some time after the event that triggered the production of the antibodies. The immune system remembers the antibodies it has come up with, and can ramp up their production quickly if the antigen is re-encountered, but the question is whether this reaction is quick enough to prevent HIV infection. IIRC people with who produce broadly neutralizing antibodies naturally still eventually develop AIDS, if left untreated. Time has to tell if vaccinated individuals behave more like those animal models, or more like that subset of people who produce broadly neutralizing antibodies a few years post infection. Until now, every vaccine for HIV has failed, and there have been many attempts. But you never win if you never try :).

est31 6y ago

Passive immunization with broadly neutralizing antibodies have been shown to prevent HIV infection in various animal studies. The goal is apparently to make the immune system able to manufacture such antibodies. The human immune system is fundamentally able to come up with these antibodies on its own, as some HIV positive individuals do develop them, but at least during natural infection they don't appear in everyone. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4604566/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4604566/ However, antibody levels won't be as high in vaccinated individuals as they are in those passive immunization animal studies, at least not forever. The body can't afford to produce full levels of antibodies for all antigens all the time. Instead, human bodies reduce produced antibody levels some time after the event that triggered the production of the antibodies. The immune system remembers the antibodies it has come up with, and can ramp up their production quickly if the antigen is re-encountered, but the question is whether this reaction is quick enough to prevent HIV infection. IIRC people with who produce broadly neutralizing antibodies naturally still eventually develop AIDS, if left untreated. Time has to tell if vaccinated individuals behave more like those animal models, or more like that subset of people who produce broadly neutralizing antibodies a few years post infection. Until now, every vaccine for HIV has failed, and there have been many attempts. But you never win if you never try :).