Accidentally? I think not. And the timeline is inaccurate, SV40 cross-contamination in vaccines was never eradicated. It still exists.
‘Simian virus 40 (SV40) is a monkey virus which was accidentally administered to humans, in the years 1955-’63, through contaminated poliovirus vaccines.
SV40 footprints in humans have been found associated at high prevalence with specific tumor types such as brain and bone tumors, mesotheliomas and lymphomas and with kidney diseases, and at lower prevalence in blood samples from healthy donors.’ Infectious Agents and Cancer, BioMed Central (BMC)
‘These data cumulatively indicate that SV40, or a closely related polyomavirus, is circulating in humans…The existence of an SV40-like human polyomavirus, which is still unknown, cannot be ruled out. Recently, a new lymphotropic polyomavirus (HPyV9) was identified in humans (286). It turned out that HPyV9 has great homology with the monkey LPyV, which has been known since the 1960s (287).’ Association Between Simian Virus 40 and Human Tumors, Front. Oncol., 24 July 2019, Sec. Molecular and Cellular Oncology, Volume 9 – 2019

