[lepton]

The increased risk was principally among a group of people who had pre-existing levels of immunity to a common cold virus known as adenovirus type 5, which was modified to become a critical part of the vaccine. Researchers emphasized that the vaccine itself could not cause AIDS, but one theory is that the cold virus may have activated the immune system in some way to make certain recipients more susceptible to becoming H.I.V.-infected when they were exposed to the AIDS virus.

Or....the immune system took apart the vaccine without benefiting from the HIV part...and then the recipients acted even more irresponsibly than usual.

[neverdem]

and then the recipients acted even more irresponsibly than usual.

We have a mind reader.