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 associates2 in Mexico and of Plotkin and Koprowski3 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
Sabin AB, Ramos-Alvarez M, Alvarez-Amezquita J, Pelon W, Michaels RH, Spigland I, Koch MA, Barnes JM, Rhim JS. Live, Orally Given Poliovirus VaccineEffects of Rapid Mass Immunization on Population Under Conditions of Massive Enteric Infection With Other Viruses. JAMA. 1984;251(22):2988–2993. doi:10.1001/jama.1984.03340460066028