Is Truvada As Effective At Preventing HIV Infection As We Thought? Maybe not.

uptown-hivA few months ago, the New York Times published an op-ed piece hailing “HIV-preventing miracle drug” Truvada as a new “sexual revolution” for the gay male community, likening it to the invention of birth control and wondering if it has the power to lower the “viral load of a city.”

Sounds pretty great, especially given that “99 percent” effectiveness number that gets thrown around. New York Magazine recently published a cover story about the drug, examining how it could “revolutionize gay life.”

Except this week the Times published another piece on the little blue pill (not an op-ed), this one called “Is Truvada, the Pill to Prevent H.I.V., 99 Percent Effective? Don’t Be So Sure.”

The article focuses on how that magic 99 number was reached, notably remarking that:

“The 99 percent figure isn’t a study finding; it’s a statistical estimate, based on a number of assumptions that are reasonable, but debatable.”

Based on tangible research data, Truvada’s effectiveness at preventing HIV infection when taken as prescribed — that is, every day — is somewhere between 90-99 percent.

And even if you consider the low end — 90 percent — it’s still a breakthrough tool to combat the spread of infection.

But the Times piece points out a big psychological gap between 90 percent and 99 percent.

The failure of a 90-percent effective method is terrible luck; the failure of a 99-percent effective method is verging on a freakish accident. Putting too much weight on the 99-percent figure may lead some PrEP users to perceive virtually zero H.I.V. risk when they should really be thinking about very low risk.

So while some see PrEP as a gateway to the sexual liberation our community celebrated in the pre-AIDS world, the reality is, like most things, more complicated.

Tim Horn, H.I.V. Project Director at the H.I.V. think-tank Treatment Action Group, said:

“Though it is possible that efficacy can approach 99 percent — language in the lay literature seems to be growing increasingly casual as to what this really means — the data supporting this currently exist in a vacuum.

Head to the Times to read the full article.