Live, orally given poliovirus vaccine. Effects of rapid mass immunization on population under conditions of massive enteric infection with other viruses. 1960.
Year: 1999
Type: article
Study design: Clinical Trial
Abstract: EFFECTS OF RAPID MASS IMMUNIZATION ON POPULATION UNDER CONDITIONS OF MASSIVE ENTERIC INFECTION WITH OTHER VIRUSES IN THE absence of enteric infection with other viruses, the feeding of a single type of live poliovirus vaccine to children who have not previously been infected with the same type of poliovirus usually results in viral multiplication in the intestinal tract, antibody formation, and complete or partial resistance to reinfection. The use of live poliovirus vaccine in areas with climatic and hygienic conditions which permit extensive dissemination of naturally occurring polioviruses and other enteric viruses throughout the year has been complicated by the problem of viral interference,(1) which we have attempted to overcome by the tactics to be described in this communication. The studies of one of us (M.R.-A.) and associates(2) in Mexico and of Plotkin and Koprowski(3) in the Belgian Congo have shown that vaccination programs in large subtropical or tropical cities that are spread out over a period of many weeks and include only a small fraction of the susceptible population not only fail to immunize a considerable proportion of the vaccinated children but also have little or no influence on the dissemination of the ever-present, naturally occurring paralytogenic strains of poliovirus. Accordingly, it seemed necessary to determine whether at least temporary dominance over the naturally occurring polioviruses and other interfering enteric viruses could be achieved by feeding a mixture of all three types of poliovirus vaccine to almost all susceptible children within a period of a few days. The reason for using a trivalent mixture instead of feeding the three types separately at intervals of four to six weeks, which is regarded as optimum during the cold months of the year in temperate zones, was to implant all three types of the vaccine strains in the largest number of children and then let nature help in their further dissemination in the community. Methods of Study and Results This study was carried out in Toluca, Mexico, in August, 1959. One of us (M.R.-A.) and his associates in Mexico were responsible for the field work and the collection of specimens, and all the virological and serologic work was carried out in Cincinnati. Toluca, located at a latitude of about 19 degrees north, has a total population of about 100,000. A serologic survey of the population just before initiation of the vaccine program indicated that 90 to 100% of the children become immune to all three types of poliovirus during the first 4 years of life (fig. 1). According to available data for the past five years, this city has been paying an average price of 14 paralytic cases per year for this naturally acquired immunity. Twenty cases of paralytic poliomyelitis had already been reported in 1959, when our study began during the second week of August. Rectal swabbings from 1,892 persons--children aged from birth to 10 years and their mothers-obtained at random in different parts of the city within a few days before the vaccination program, were each tested in monkey kidney and human epithelioma (HEP 2) tissue cultures as well as in newborn mice. The results, summarized in figure 2, indicate that the special methods used revealed a much higher incidence of natural enteric viral infection than has ever been demonstrated before-beginning during the first days after birth and reaching a peak of 72% during the 1st year of life. Beginning with 1-month-old children, polioviruses were isolated from every age group tested, with a peak rate of 14 to 15% in children between 7 months and 2 years of age. The high infection rate among the mothers of these young children was surprising-5% for polioviruses and 16% for other enteric viruses. [Figures 1-2 ILLUSTRATION OMITTED] It was in this setting that a single close of trivalent poliovirus vaccine ([10.sup.5.2] to [10.sup.5.6] 50% tissue-culture dose [[TCD. …
Source: PubMed Central
Authors: A B Sabin, M Ramos-Alvarez, J Alvarez-Amezquita, W Pelon, R H Michaels, I Spigland, M A Koch, J M Barnes, J S Rhim
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W304498692