Report from the AIDS/Poliovirus Advisory Committee

CONFIDENTIAL
infectivity. Furthermore, the poliovirus stock used in Congo was diluted with salt
solution approximately 300 fold to obtain the final vaccine preparation.
In summary, the possible presence of SW or related virus particles in the
vaccine preparation cannot be discounted. However, if present, the concentration of
SIV particles is likely to have been extremely low.
2) Administration. In the Congo trial -lml of vaccine was administered to
each individual by squirting into the oral cavity with the use of an automatic
syringe. About 300,000 individuals were vaccinated. The oral route is not an
efficient way of infection by SIV or HIV, which are generally transmitted through
blood or sexual contact. It is possible, however, that some of the vaccinated
individuals had sores, wounds or blisters in their oral cavity, thus increasing the
chances of infection. In addition, there is evidence that the virus can be transmitted
on rare occasions from mother to newborn via breast-milk, suggesting an oral or
gastrointestinal route of transmission in infants. In any case, the chances of SW or
HIV being successfully transmitted through the method of administration used for
the polio vaccine are low.
The vaccine trials conducted in Africa were carried out mostly by squirting
the vaccine aliquots through an automatic syringe into the mouths of recipients. In
contrast, the Sabin attenuated poliovirus vaccine, which was also produced in
monkey kidney cells, was distributed to millions of recipients in Eastern Europe, in
sugar cubes. Considerable emphasis has been given by Curtis to the different
methods of distribution as a possible explanation for the fact that the AIDS epidemic
did not start in Eastern Europe. We find this argument to carry little weight.
Sucking a sugar cube would give a virus particle approximately the same likelihood
to reach a susceptible cell or wound in the oral cavity as mouth squirting of the
same amount of fluid. Aerosolization could conceivably increase the chances of the
virus reaching the respiratory tract and alveolar macrophages, but aerosolization
deep into the lung is not likely to have been common.
3) Multiplication in human subjects of the putatively transmitted monkey
virus. If SIV or an SWV-like virus did gain access to a susceptible cell in a vaccine
recipient, it is possible that it might have multiplied in the human host. There are

two known types of human immunodeficiency virus, HIV-1 and HIV-2. HIV-1 is

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