The way you've phrased this, it sounds like you are casting "other hard to cure STDs" as a protective measure against the "threat of 1960s style of unprotected

The way you've phrased this, it sounds like you are casting "other hard to cure STDs" as a protective measure against the "threat of 1960s style of unprotected sex wave." I read it as him casting the threat of those 'hard to cure STDs' as an incentive for people to not take the 1% risk of HIV infection.