How did you determine that AIDS was caused by a virus?
We had just discovered the first and the second human retrovirus and I had reason think that AIDS (the disease we were hearing about) might be due to just this kind of virus, still another human retrovirus. This idea came from discussions with Dr Max Essex at Harvard with me when we began thinking about two things. Essex had great expertise with the leukemia virus in cats and he pointed out that with minor changes in the protein that is one of the surface proteins, called the envelope protein, minor changes of that, of the cat leukemia virus and that virus no longer caused leukemia but could cause immune impairment. Kind of the opposite. Instead of too many cells, too few cells. In our experience with the first human retrovirus, which we named Human T-cell Leukemia Virus 1 (HTLV-1), this virus, my colleagues and I discovered as the first human retrovirus in the period of 1979-1980. It causes an unusual form of cancer, leukemia of T-cells in young adults. And our experience with that virus was as follows: it infected exactly these kinds of cells, CD4 T-cells, T-helper cells. It was transmitted by blood and by sex and by mother to child. Little by little as we heard from the CDC, particularly from Curran this is a disease that seemed to favor certain groups where there was sexual activity or a baby born from a certain mother, who had AIDS, could get AIDS or blood transfusion recipient. So that fit this kind of virus and we also knew that this virus, even when it didn't cause leukemia, could give mild impairment of our immune system. Well, what about a modification of that virus? Might cause major impairment and be transmitted the same way. Furthermore, we were learning that there was a lot of AIDS in Haiti and it seemed to be that the origin might be in equatorial Africa. And we knew that the HTLV-1 was prevalent in Haiti and may have had its origin in Africa, and was common in some tribes in Africa, in the African rainforest and so on. So, we speculated that AIDS might be due to another retrovirus belonging to this greater HTLV family...new...but belonging to that family. This idea, was the one that bore fruit, the only idea that bore fruit but, in its details was wrong because mother nature what didn't turn out to be so simple...it's a retrovirus, the AIDS virus HIV, but it's a whole new family.
