SV40 Contamination

About SV40 Contamination

In 1960, scientists discovered that polio vaccines distributed between 1955 and 1963 were contaminated with Simian Virus 40 SV40 from monkey kidney cells used for vaccine production. Millions of people received SV40 contaminated vaccine. Concerns that SV40 caused cancer in humans were investigated extensively. The Institute of Medicine concluded in 2002 that evidence was insufficient to confirm or rule out a causal relationship. Subsequent studies have generally found no increased cancer risk in SV40 exposed populations. The contamination led to improved screening of cell substrates for vaccine production. The SV40 episode is sometimes cited by anti vaccine activists as evidence of vaccine dangers, though the scientific consensus is that the contamination did not cause widespread harm. The case illustrates the importance of continuous safety monitoring.