A federal government agency knowingly released polio vaccine contaminated with a monkey virus in the 1960s that has since been linked to a range of cancers, including mesothelioma.
The virus contaminated at least four batches of vaccine totalling almost three million doses between 1956 and 1962.
Two of the batches were released after testing positive to contamination. The other two were released before tests could be done. An unknown number of earlier batches were also almost certainly contaminated.
An investigation by The Age has found documents from the Commonwealth Serum Laboratories which reveal bosses there released one batch of about 700,000 doses of contaminated vaccine in 1962 on the grounds that “much vaccine issued in the past was probably similarly contaminated”.
Australia’s leading experts on the virus, which is known as simian virus 40 or SV40, have found traces of it in human tumour cells and are calling for urgent funding to clarify the links.
Commonwealth Serum Laboratories knew from its own internal research that the monkey virus was a potential cause of cancer in humans. The research, which was never made public, was carried out in August 1962, while contaminated batches of vaccine were still being released. Tests carried out at the time also showed monkey virus contamination of some of the “seed” polio virus used to produce all Salk polio vaccines between 1956 and 1962.
Commonwealth Serum Laboratories produced more than 18 million doses of Salk polio vaccine, enough to vaccinate six million Australians, during that period. Nine out of every 10 Australian children aged between 5 and 14 are estimated to have been injected with Salk vaccine by 1965, when it was replaced with Sabin oral vaccine. Polio vaccinations were given to children as young as three months.
SV40 was known to have contaminated polio vaccines in the United States and other countries before 1963. A spokeswoman for the federal Health Department said the charge that Australian polio vaccines may have been contaminated had been previously acknowledged but no proof had been found.
Scientists have already linked SV40, which is known to cause cancers in small animals, to a range of rare human lung, brain and blood cancers, but opinion is split on whether the virus actually causes human cancer.
Professor Bruce Robinson, of the University of Western Australia’s school of medicine, and Dr Roger Reddel, head of the Cancer Research Unit at the Children’s Medical Research Institute at Westmead Hospital, say more research needs to be done in light of the vaccine revelations.
Professor Robinson, who has found SV40 traces in meso-thelioma lung tumours in Australian patients, said relatively little research had been done locally on SV40. “We do need to know what’s going on in this country because we have the world’s highest incidence [of mesothelioma],” he said.
said that while the “jury is still well out” on whether the virus causes cancer, “I really still think there is a case to be answered and it needs a lot more research”.
A spokeswoman for the federal Health Department said Australia’s medicines watchdog, the Therapeutic Goods Administration, was monitoring research by the US Centres for Disease Control into SV40 and cancer.
She said vaccine manufacturers now followed strict safety guidelines, with all vaccines on the Australian market being thoroughly tested before release.
Commonwealth Serum Laboratories, which was privatised in 1994, supports the call for further research. Its director of public affairs, Rachel David, said establishing whether SV40 caused cancer would be difficult, but “I don’t discount the debate that’s going on”.
She said the company’s practices had changed dramatically and the public could be “very confident about the quality and safety of vaccines being produced at the moment”.
She said the decision to release contaminated vaccine would have been reached after “balancing off” the very real risk of polio epidemics against what was at the time a “small theoretical risk” from the monkey virus. “We stand by the safety of what we produce now, but to go back 40 years and start talking about the decisions that people were making in that environment, I can’t pass judgement on that,” she said.
Polio vaccinations are no longer routinely given in Australia following the declaration in 2001 that the western Pacific region was polio-free.
Documents held in the National Archives relating to Commonwealth Serum Laboratories’ production of Salk polio vaccine show that the first tests for SV40 were carried out in February 1962, after the alarm was raised internationally in 1961 of possible contamination.
They were found earlier this year by a Melbourne researcher, Brenda Coughlan, who was searching for material for a book.
SV40 came from pulped infected monkey kidneys used to produce cell cultures to grow the polio virus. The polio virus was then killed using formaldehyde to produce the vaccine, but SV40 survived the process.
The Age confirmed the contents of the documents, including research work notes, with the biochemist who carried out the SV40 testing in 1962 for Commonwealth Serum Laboratories. His name is John Withell and he was later head of the Therapeutic Goods Administration’s laboratory in Canberra.
Minutes of a meeting held at Commonwealth Serum Laboratories on May 1, 1962 record how the organisation’s then director, Ron Greville, confirmed that SV40 had been found in vaccine batch number 64, which was being readied for release.
“Dr Greville opened the discussion by stating that although SV40 was present in batch 64, the batch would be issued; a decision which was founded on the belief that probably much vaccine issued in the past was probably similarly contaminated,” the minutes say.
The agency’s records show that batch 64 was officially released in December 1962.
Mr Withell’s research results show that three other batches of vaccine also tested positive for SV40: batch 49, released in October 1959, batch 63, released in February 1962 and batch 65, released in January 1963. Batch 66 was also positive, and was destroyed after an attempt to rid it of SV40, ordered by health authorities in Canberra, killed the vaccine’s effectiveness. The authorities said no further vaccine containing living monkey virus could be released.
Later batches of vaccine were made from the kidneys of monkeys shown to be free of SV40 infection. Only one batch of those tested, number 58 released in September 1961, was negative.
Mr Withell also tested three “seed” polio viruses that had been originally obtained from the Salk laboratories in the US in 1955 and used to manufacture Australian polio vaccines.
His test results contained in the National Archives show that one of the seed viruses was heavily contaminated with SV40.
“Type two [polio seed virus] was stuffed full of SV40,” Mr Withell said.
He stressed that the negative results for the other two types of polio seed virus did not necessarily show they were free from SV40, because the test was not sensitive enough.
Research notes also show that in August 1962 Mr Withell tested the effect of SV40 on human embryo cells. The SV40 caused “transformation” in the cells, which indicated it was potentially carcinogenic.
Mr Withell said the results were reported to an internal research panel for Commonwealth Serum Laboratories, but were never made public.