Simultaneous feeding of multiple types of living attenuated polioviruses as a trivalent vaccine is limited by interference between strains in the human gut.
A survey of the literature to date on feeding living attenuated polioviruses for the immunization of man reveals that relatively little has been reported on simultaneous feeding of the three types of virus or the use of mixtures of them as a trivalent vaccine. This is apparently due to the fact that certain strains of poliovirus were found to interfere with the establishment and multiplication of other type strains in the human gut. Thus, In a subsequent study Koprowski et al. (1956) attempted to overcome this interference by feeding much larger doses of type II virus in a mixture with type I. Again interference was found to occur between the two types, though, under the conditions of the latter study, type I strain was not always dominant.
Cox et al. (1959) conducted a review in Poliomyelitis. Trivalent Oral Poliomyelitis Vaccine was evaluated on Interference between poliovirus strains. Simultaneous feeding of multiple types of living attenuated polioviruses as a trivalent vaccine is limited by interference between strains in the human gut.