“We are in a golden age in HIV vaccine science.”

December 2, 2017 10:28 AM

On the eve of World AIDS Day, the NIH announced two new large clinical trials. HPTN 084 will test the efficacy of a long-acting injectable drug in volunteers in southern and eastern Africa. Imbokodo will recruit women in southern Africa to test the efficacy of a mosaic vaccine designed to induce immune responses against a variety of strains of HIV. Also see the South African Medical Research Council announcement.

These trials follow HVTN 702, an efficacy trial for another vaccine which opened last year in South Africa. This was the first HIV vaccine efficacy trial to open in seven years, and tests a vaccine based on the RV144 regimen. Prior to 2016, six efficacy studies tested four vaccine approaches, and only RV144 found modest efficacy of about 30% reduction in risk of infection. 60% is the preferable minimum efficacy for a new vaccine, though 50% would still have a big impact.

Relatedly, the AMP (Antibody Mediated Prevention) trials are testing the ability of passively infused antibodies to prevent HIV infection, and new broadly neutralizing antibodies are on the way.

Note that the vaccine and AMP trials are placebo-controlled and PrEP is not part of the interventions being tested. More on PrEP in HIV prevention studies from the perspective of advocates and community members may be found here and here.

Ethical consideration for biomedical HIV prevention research are laid out by UNAIDS.

Read more about proven and experimental approaches to HIV prevention here.

posted by esoterrica (5 comments total)

PrEP stands for Pre-Exposure Prophylaxis, and the simple explanation is that it's a daily pill that can prevent an HIV- person from getting HIV. (I mention this because it's come up before in these discussions that most people are unaware this medical option exists.)
posted by roger ackroyd at 11:31 AM on December 2, 2017 [2 favorites]

A proven long-acting injectable would make an incredible difference in the lives of so many people.
posted by BlueHorse at 5:37 PM on December 2, 2017

Small point of clarification: the vaccine is actually being tested against PrEP, not a placebo--that would be pretty unethical!

Injectable PrEP is also great for people with a cervix, as oral PrEP has a longer lead-up time to efficacy and the dosing regime is less forgiving than that of people taking it for whom anal sex is the primary risk.

It's pretty incredible how far HIV medicine has come.
posted by stillmoving at 5:11 AM on December 3, 2017

Extremely worth mentioning while we are on the subject: PEP (Post-exposure prophylaxis) is also an effective treatment that can block an HIV infection if administered immediately. If you think you've been exposed to HIV, go to an ER immediately and insist on seeing a doctor who is familiar with PEP. Call 911 if you have to -- you are experiencing a medical emergency that is treatable, but only within a small window of time.

PrEP is obviously preferable if it's an option, but it's worth knowing that there are effective emergency treatments for HIV exposure.
posted by schmod at 11:16 AM on December 3, 2017 [2 favorites]

Great post- I'm realizing how out of date I was on the status of HIV science, because I didn't really know that something like PEP was widely available, and I didn't know that a long-acting injectable could be on the way. HIV kind of dwells in the back of my mind as a "welp, that's something we can't do much about but I guess we'll get there eventually" problem when in fact, we have, and are, doing a lot. This is positive news!
posted by Secretariat at 1:25 PM on December 5, 2017