Turned up to eleven: Fair and Balanced

Wednesday, April 21, 2004

A vaccine-disease theory put to rest
I have been interested in the "vaccine as cause of disease" notion for some time, the most immediately relevant ones being thimerosal/autism and MMR/autism. Without getting to deep into those ones, I will say that there is valid cause for concern about the level of thimerosal that was in childhood vaccines (it was removed in 1997, IIRC), but the jury is still out. If it turns out that autism rates fall dramatically over the next 5-10 years, then that would be solid potential evidence (with proper epidemiological analysis, of course). However, one of the more outlandish but persistent theories was the HIV in polio vaccine hypothesis. A recent issue of The Scientist cites a report in Nature putting the final nail in the coffin of this theory. An excerpt;

The final nail is in the coffin for the now largely refuted theory that the human immunodeficiency virus type 1 (HIV-1) crossed into humans as a result of contamination of oral polio vaccine (OPV), according to a new study. In the April 22 Nature, Michael Worobey and colleagues report that the chimpanzees claimed to be the source of simian immunodeficiency virus (SIVcpz) that crossed over actually contain a SIVcpz unrelated to HIV-1.

“Scientifically, this paper spells the end of the OPV theory,” said Edward Holmes, from the University of Oxford, who was not involved in the study.

The OPV/AIDS theory holds that chimpanzees from the Kisangani (previously Stanleyville) area in the Democratic Republic of Congo that were purportedly used in the preparation of OPV transmitted a SIVcpz to humans. Evidence against this has been piling up, first with the absence of SIVcpz or chimpanzee DNA in old OPV stocks and then with data suggesting HIV originated 30 years before the OPV trails.

By the way, while I am glad to find that this theory has been discredited, I in no way mean to imply that anything wrt thimerosal/autism has similarly been discredited. However, it is worth noting that vaccination is the single most effective public health tool in existence, and has been responsible for a tremendous improvement in the quality of life over the last century or so. It is nice to see that good science is winning out in the search for answers in this arena.