The Cutter Incident
In April 1955 more than 200,000 children in five Western and mid-Western USA states received a polio vaccine in which the process of inactivating the live virus proved to be defective. Within days there were reports of paralysis and within a month the first mass vaccination programme against polio had to be abandoned. Subsequent investigations revealed that the vaccine, manufactured by the California-based family firm of Cutter Laboratories, had caused 40,000 cases of polio [20%], leaving 200 [1%] children with varying degrees of paralysis and killing 10 [0.005%].
As a result, `vaccines were among the first medical products almost eliminated by lawsuits'. Indeed, the National Vaccine Injury Compensation Program was introduced in 1986 to protect vaccine manufacturers from litigation on a scale that threatened the continuing production of vaccines.
SV40 Contamination and Cancer
Some of the polio vaccine administered from 1955–1963 [8 years] was contaminated with a virus, called simian virus 40 (SV40). The virus came from the monkey kidney cell cultures used to produce the vaccine. Most, but not all, of the contamination was in the inactivated polio vaccine (IPV).
Cancer risk associated with simian virus 40 contaminated polio vaccine
Conclusions: These data suggest that there may be an increased incidence of certain cancers among the 98 million persons exposed to contaminated polio vaccine in the U.S.; further investigations are clearly justified.
Materials and methods: Using data from SEER, we analyzed the incidence of brain tumors, bone tumors, and mesotheliomas from 1973-1993 and the possible relationship of these tumors with the administration of the SV40 contaminated vaccine.
Results: Our analysis indicates increased rates of ependymomas (37%), osteogenic sarcomas (26%), other bone tumors (34%) and mesothelioma (90%) among those in the exposed as compared to the unexposed birth cohort.
"vaccine-derived" polio outbreaks
In 2015, the WHO declared Type-2 wild polio eradicated. But the problem was that the oral polio vaccine still contained live weakened Type-2 virus and while the wild Type-2 was gone, occasionally there continued to be outbreaks of vaccine-derived Type-2 polio.
vaccine-derived poliovirus type 2
In 2020, 959 human cases of circulating vaccine-derived poliovirus type 2 (cVDPV2) and 411 cVDPV2-positive environmental samples were reported globally from 27 countries, of which 21 countries were from the African Region and six countries from reported from the regions of the Eastern Mediterranean, Europe and the Western Pacific. The number of cVDPV cases and environmental samples increased in 2020 compared to 2019 when 366 cVDPV2 cases and 173 cVDPV2-positive environmental samples were reported.
No on-going Polio Boosters?
Routine poliovirus vaccination of U.S. adults (i.e., persons aged >18 years) is not necessary. Most adults do not need polio vaccine because they were already vaccinated as children and their risk of exposure to polioviruses in the United States is minimal.
Poliomyelitis
Polio is a highly infectious disease caused by a virus. It invades the nervous system, and can cause total paralysis in a matter of hours. The virus is transmitted by person-to-person spread mainly through the faecal-oral route or, less frequently, by a common vehicle (for example, contaminated water or food) and multiplies in the intestine. Initial symptoms are fever, fatigue, headache, vomiting, stiffness of the neck and pain in the limbs. 1 in 200 infections leads to irreversible paralysis (usually in the legs). Among those paralysed, 5% to 10% die when their breathing muscles become immobilized.
People most at risk
Polio mainly affects children under 5 years of age.
Prevention
There is no cure for polio, it can only be prevented. Polio vaccine, given multiple times, can protect a child for life.
Global caseload
Wild poliovirus cases have decreased by over 99% since 1988, from an estimated 350 000 cases in more than 125 endemic countries then, to 33 reported cases in 2018.
Of the 3 strains of wild poliovirus (type 1, type 2, and type 3), wild poliovirus type 2 was eradicated in 1999 and no case of wild poliovirus type 3 has been found since the last reported case in Nigeria in November 2012.
Polio through history
Polio epidemics did not begin to occur until the latter part of the 19th century, but evidence indicates that polio is an ancient disease. A well-known stele from the 18th dynasty of ancient Egypt (1570–1342 BCE) clearly depicts a priest with a telltale paralysis and withering of his lower right leg and foot. The mummy of the pharaoh Siptah from the late 19th dynasty (1342–1197 BCE) shows a similarly characteristic deformity of the left leg and foot. However, because of the sporadic appearance of the infection, the absence of epidemics until relatively recent times, and the nonspecific nature and infrequency of the acute illness, there is hardly another recognizable trace of the disease until the 18th century. In 1789 a pediatrician in London, Michael Underwood, published the first clear description of paralytic disease of infants in a medical textbook. In the early 19th century, small groups of polio-afflicted patients began to be reported in the medical literature, but still only as sporadic cases.
It is an irony of medical history that the transformation of polio into an epidemic disease occurred only in those industrialized countries in North America and Europe that had experienced significant improvements in hygiene during the 19th and 20th centuries. That has led health experts to conjecture that the infection was common in earlier times but that people were exposed and infected (in typically unhygienic environments) at very young ages, when they were less likely to suffer permanent paralysis as an outcome. As hygiene improved, the certainty of young people of successive generations being exposed to the virus was gradually reduced, and in that new situation it was not long before enough susceptible children and adults had accumulated to allow epidemics to break out.
Why End Polio?
To end polio, we must stop transmission of the virus in the two countries where it remains endemic: Afghanistan and Pakistan. We must also keep all other countries polio-free until we're certain it won't resurface. Up to 60 high-risk countries still operate large-scale immunization campaigns to protect children against polio.
