Between 1970 and 1984, Romania participated in the safety trials of an oral vaccine sponsored by the WHO. It turned out, that, for unexplained reasons, the incidence of the vaccine-associated paralytic poliomyelitis (VAPP) is 5-17 higher in Romania than in other countries. It was first believed that the vaccine in Romania was too virulent, but replacing it with a different vaccine did not change the VAPP incidence. It turned out that 87% of paralyzed children received intramuscular injections 30 days before the onset of paralysis (17 injections on average), as compared to 51% of non-paralyzed children (3 injections on average). Each injection increased the risk of paralysis by 13%. Paralysis was observed 8 times more often in those who received one injection, and 182 times more often in those who received over 10 injections. Overall, 86% of VAPP cases were caused by injections.
The fact that injections and vaccines provoke paralysis was known already back in 1950.
Some children of the polio epidemic in Melbourne in 1949 developed paralytic poliomyelitis soon after getting pertussis and diphtheria vaccine. Doctors denied any connection. It turned out, however, that such connection existed, since in most cases, paralysis developed precisely in the injected leg or hand. The authorities thought for a long time whether they should communicate this information to the doctors and general public, and decided to tell about pertussis, but not diphtheria. The press did not blow up the story, and the future of vaccination was not called into question.
The connection between poliomyelitis and injections was recognized in 1950 in Australia and the UK, and later in the USA. It was confirmed by testing on monkeys in 1954. They started to give injections in the winter, and it reduced the number of paralysis cases caused by injections, to a minimum. The authors of a 1985 article reviewed the literature and showed that the risk of paralysis due to injections can increase by 25 times, and that repeat injections, especially of arsenic and penicillin, significantly increase the risk of paralysis, as compared to a single injection.
An experiment on mice was conducted in 1998, and found that, indeed, muscle injury from injections increases the risk of paralysis from poliovirus, and the mechanism of how it enters the nervous system was described. Other enteroviruses can also cause poliomyelitis, although how exactly they enter the nervous system in unknown.
Nothing changed since the 1950s, however. There was a poliomyelitis outbreak in Oman in 1988-1989, despite the 87% vaccination coverage. No association between the number of vaccine doses and paralysis was found. However, a lot more children who received a DTP vaccine within past 30 days got sick. 25% of children got sick because of the DTP vaccine. In 1993, 89% of 152 children suffering from paralytic poliomyelitis received an unnecessary injection 48 hours prior to the onset of paralysis. Almost always the paralysis developed at the injection site. Other studies in Pakistan showed a similar pattern. The same was observed in India.
Но с 1950-х ничего не меняется. В 1993 году из 152-х детей с паралитическим полиомиелитом в Пакистане 89% получили ненужную инъекцию за 48 часов до начала паралича. Паралич почти всегда развивался в месте укола. В других исследованиях в Пакистане наблюдалась похожая картина.
То же самое наблюдается и в Индии.
Сегодня тоже во многих странах OPV совмещают с уколами других вакцин.