It's not completely unheard of, but this is the first time I've heard of someone actually doing it.
I saw on a PBS special once about AIDS how when it first broke out, there were those people that were directly exposed to the virus, yet the virus never infected them, and they never got sick. One researcher in the 80s speculated there was a mutation in those people that prevented the HIV virus from ever infecting their cells, and the virus just died as a result.
They had determined early on that the HIV virus invades cells much the same way that the black plague did when it ravaged Europe. They wanted to know why, and speculated that a mutation called Delta 32 I believe, was responsible for why some people during the time of the black plague either got sick, but got better, or never got sick at all. They did discover that the descendants of those people had this mutation, and judging from the percentage of how many people had it, and then going back 400 years, they determined that at the time the plague hit, the mutation was extremely strong in those survivors.
So they thought that maybe the mutation might also protect against HIV as well, and in those people they tested whose blood continuously resisted infection from HIV, they found that mutation.
Not sure if anyone else ever saw that PBS program.