Polio Vaccine Not Tied to Non-Hodgkin Lymphoma

Norwegian researchers report finding no support for the proposed link between a polio vaccine possibly contaminated with simian virus 40 (SV40) and lymphoproliferative diseases, including non-Hodgkin's lymphoma (NHL) and excluding Hodgkin's lymphoma.

The vaccine was administered between 1955 and 1963 around the world. Dr. Guri Olsen Thu and colleagues at the Cancer Registry of Norway, Montebello, Oslo, investigated the proposed link between vaccine and NHL by examining Norwegian cancer incidence data, looking at birth cohorts that the researchers assumed received the vaccine in question.

Between 1953 and 1997, the incidence of lymphoproliferative diseases tripled for both males and females. This increase was primarily due to an increase in cases of NHL.

Dr. Thu's group analyzed the data according to age, cohort and time period. "The cohort effect was more prominent than the period effect," they report in the April 15th International Journal of Cancer.

"However," the investigators conclude that "the variations in incidence patterns across the birth cohorts did not fit with the trends that would be expected if a SV40-contaminated vaccine did play a causative role" in the increase in lymphoproliferative diseases.