AIDS Origin Theory: Polio Vaccine?

In March 1992 two separate theories have been published suggesting
that AIDS may have been accidentally introduced into humans by live-
virus polio vaccines which may have been contaminated with unknown
monkey viruses. These theories are more plausible than most of the
AIDS-origin ideas which have come along. But they are still
speculative; the evidence only suggests that it is possible that AIDS
started this way, not that it actually did.
Important articles about the polio-vaccine theory have appeared
recently in ROLLING STONE, THE LANCET, and THE HOUSTON POST. Instead of
restating the points they made, this article will provide annotated
references, so that readers who are interested can go to the original
sources.
"The Origin of AIDS," by Tom Curtis, an 8,000-word article in the
March 19, 1992 ROLLING STONE, suggests that an oral polio vaccine used
in over 300,000 people in the Belgian Congo (now Zaire) in the late
1950s may have transmitted an unknown virus which may have been present
in monkey kidney cells in which the polio virus was grown during the
making of the vaccine. Use of this vaccine was apparently discontinued
in 1959, after Albert Sabin, M. D., developer of the polio vaccine in
most widespread use today, reported that an unidentified virus had been
found in it. No known monkey virus resembles HIV-1, but there are
believed to be many unknown monkey viruses; it is possible that a virus
close to HIV-1 exists but has not been discovered.
"Simian Retroviruses, Poliovaccine, and Origin of AIDS," by Walter
S. Kyle, published in THE LANCET, March 7, 1992, suggested that AIDS
might have been transmitted to the gay community in the United States by
use of the Sabin live-virus oral polio vaccine as a treatment for
herpes, before the development of acyclovir. This use was suggested by
A. Trager, in at least two articles published in 1974. The vaccine was
given orally (the same way as when used for prevention of polio, but
apparently in larger doses), once a month for three months only.
Several published letters, in English, German, French, and Hebrew,
discussed this use of the Sabin vaccine.
Kyle, a lawyer who researched vaccine safety for a legal case
concerning paralysis after contact with a vaccine, said that a
particular lot of polio vaccine was released by U. S. regulators,
despite tests in 1976 and 1977 which suggested that it may have
contained an unknown virus, probably a retrovirus.
A weakness of the theory that AIDS was spread this way is that it
does not explain why AIDS would have occurred in gay men, but not to any
of the millions of children who also took the Sabin vaccine by mouth.
Kyle had to speculate "that this virus either survived passage through
the gastrointestinal system because of the rate of exposure [referring
to the fact that the dose used was larger than those for polio
vaccination] and/or bypassed it because of the nature of the sexual
activity."
Ongoing coverage of these theories and the controversy around them
has appeared in THE HOUSTON POST, in a series of articles by Tom Curtis
(who also wrote the story in Rolling Stone). Articles have appeared on
March 15, 16, 17, and 18 (the day this issue of AIDS TREATMENT NEWS goes
to press); we expect there will be more in the future.
Perspective
We suggest that several points be kept in mind so that this
unproven but potentially important story does not do more harm than
good:
* None of the evidence presented suggests that there is any danger
of AIDS from polio vaccination today. Even if all the theories which
have been suggested are true, the only AIDS transmission from
vaccination against polio would have occurred in Africa in the 1950s,
from a vaccine which has not been used anywhere in the last three
decades. The worst thing that could happen from this story would be for
unthinking panic to interfere with important vaccination programs.
According to an expert quoted March 18 in The Houston Post, polio
vaccination is saving at least 450,000 children each year from paralytic
polio worldwide, and preventing 40,000 deaths.
* There is also no grounds for scandal, even if the theory is true.
There is always a risk of unknown danger in any new medicine, no matter
how much care is taken. Who would have wanted to not vaccinate against
polio because of the remote possibility that something unforeseen would
go wrong later?
* It is important that further tests be done, especially to analyze
"seed stocks" of early polio vaccines, which are normally preserved in
freezers in case any questions arise later. These stocks could easily
be tested for HIV.
If AIDS did originate from monkey viruses inadvertently transmitted
in vaccination programs, that would be important to know, both for
preventing any such occurrence in the future, and also for insights
which might be provided for treatment development. If the vaccine seed
stocks are free of HIV, suggesting that such transmission was unlikely,
then this is also important to know, to set peoples' minds at ease.