WASHINGTONThere is insufficient evidence to prove or disprove whether polio vaccine doses contaminated with simian virus-40 (SV40) between 1955 and 1963 can trigger certain cancers in humans, according to a report by the Institute of Medicine (IOM), a part of the National Academy of Sciences. Although most population studies have not found an increase in the cancers among people inoculated with the vaccine between 1955 and 1963, a possible link cannot be completely ruled out because of substantial statistical and design limitations in the 13 studies, an IOM committee concluded.
The committee recommended the development of sensitive blood tests and standardized techniques to more definitively detect SV40 in infected individuals. These techniques should then be used to determine the incidence of SV40 infection prior to 1955 and after 1963. This information would reveal how much of the SV40 infection in humans can be attributed to the contaminated vaccine.