Leading immunologists in the field of HIV prevention have begun research on alternatives to the pill version of PrEP, including a long-lasting injectable edition of the drug.

If these versions are approved, alternatives to the current existing model of PrEP would not be available for several years.

Anthony Fauci, the head of the National Institute of Allergy and Infectious Disease, spoke to The Washington Blade about why an injectable, long-lasting version of PrEP would be advantageous in relation to what he calls “pill fatigue”:

“People sometimes get pill fatigue, and it becomes onerous to have to take the medicine every single day of your life, particularly a medicine that you know is important for a disease that’s potentially lethal.”

Fauci continued: “So instead of having the obligation of remembering to take a pill every day, you can have an injection that you get maybe two or three times a year to allow you to essentially suppress the virus.”

The proposed treatment, which is being examined in clinical trials, is a long-acting version of pre-exposure prophylaxis which patients would be injected with once every four weeks initially. After that, the wait time between injections would be increased with patients receiving injections once every two months, and then once every four to six months.

An injectable version of PrEP may be used not only to prevent HIV, but also to treat patients in order to suppress viral loads so that they become undetectable.

In terms of long-term HIV prevention, Fauci described an injectable model as the “most promising and optimistic” option.

Also in the works are on-demand versions of PrEP, which would be made available to people on an intermittent basis. With this version, people could avail of the drug in advance of expected sexual encounters.

Fauci described this alternative as “risky”, as sexual encounters are not always predictable:

“Often people get into situations where they can’t anticipate what’s going to happen.”