Report on the outbreak of poliomyelitis during 1961 in Kingston-upon-Hull and the East Riding of Yorkshire.

  • Great Britain. Ministry of Health.
Date:
1963
Catalogue details

Licence: Public Domain Mark

Credit: Report on the outbreak of poliomyelitis during 1961 in Kingston-upon-Hull and the East Riding of Yorkshire. Source: Wellcome Collection.

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    Routine Immunization In the use of oral vaccine for routine immunization the aim is to produce alimentary infection and to stimulate antibody formation. For the comple- tion of immunization at least two and preferably three doses of trivalent vaccine are required because of the competition which exists between simul- taneously administered polioviruses. This competition is believed to be due to virus interference—a phenomenon which may be exhibited between viruses of the same species such as polioviruses or between the vaccine and other viruses such as the Coxsackie or ECHO viruses or even adenoviruses. Mutual interference between polioviruses perhaps depends on some quality such as the degree of infectiousness of the viruses. The different types of the three Sabin attenuated viruses differ in this property and the Sabin Type 2 virus given in a trivalent vaccine composed of equal amounts of the three viruses interferes with the successful implantation of the other two viruses in a proportion of instances (Report of the Public Health Laboratory Service, 1961 ; Hale, Lee and Gardner, 196la). In persons who respond to the Type 2 strain but not to the Types 1 or 3 on the first occasion when trivalent vaccine is given, the second dose of oral vaccine is followed by a satisfactory formation of antibodies to Types 1 and 3 presumably because Type 2 can no longer re-infect the alimentary canal. The occurrence of an outbreak of poliomyelitis in a population in whom a large proportion of the most susceptible persons have received inactivated poliovirus vaccine is clearly an indication of a relative failure of immuniza- tion. Intensification of routine immunization with particular effort to obtain cooperation from those who have never received vaccine is one method of dealing with the situation, but requires time. Mass immunization with oral vaccine differs from that with inactivated vaccine in that it offers the possibility of utilising the interference phenomenon as well as of achieving specific immunization. For interference to succeed in preventing further spread of the epidemic virus it is necessary rapidly to obtain colonisation of the alimentary canal in as many persons as possible. That this has in fact been achieved may be judged from the various outbreaks in which oral vaccine has already been used. | . Mass use of oral vaccine during outbreaks The first use of oral poliovirus vaccine during an outbreak of poliomyelitis was in the Belgian Congo towards the end of 1957. Courtois, Flack, Jervis, Koprowski and Ninane (1958) gave the Koprowski Chat Type 1 virus vaccine to all of the few thousand inhabitants of four villages in the Congo among whom a few cases of poliomyelitis had already occurred. No cases were observed after the vaccine was used on this limited scale. In 1958, a sharp outbreak of poliomyelitis due to Type 1 poliovirus occurred in Singapore. Large-scale administration of Sabin Type 2 vaccine was begun in ithe twelfth week of the outbreak and continued for twelve weeks thereafter during which 200,000 of the half-million children under 10 years of age were vaccinated. (Hale, Lee, Doraisingham, Kanagaratnam, Leong and Monteiro, 1959). The protective effect of the vaccine was assessed by Knowelden, Hale, Gardner and Lee (1961) who compared the number of cases of poliomyelitis in vacci- nated and unvaccinated children week-by-week. No sparing effect on paralytic disease was found until an interval of.8 or more days had elapsed after the