Does a vaccination schedule combining live and inactivated poliovirus vaccines reduce the incidence of poliomyelitis in Gaza compared to TOPV alone?
Combining live and inactivated poliovirus vaccines successfully controlled poliomyelitis in a developing region where the oral vaccine alone was insufficient.
Trivalent oral poliovirus vaccine ( TOPV ) has been used in Gaza since 1967. After an initial decrease of 33% in the incidence of the paralytic disease, no further decrease could be noted. The mean annual incidence until 1977 was 10 per 100,000 inhabitants. Two outbreaks caused by poliovirus type 1 were registered in 1974 and 1976 with an incidence of 18 per 100,000 inhabitants. In these outbreaks, 34% and 50% of the affected children, respectively, had received three to four doses of TOPV . A new vaccination schedule was introduced in 1978, combining live and inactivated poliovirus vaccines. In the years 1978-1980, the incidence decreased to 2.6 per 100,000 inhabitants; and during 1981-1982, only three cases were recorded. These results indicate that a schedule like the one used in Gaza could serve as a model to control poliomyelitis in developing countries where TOPV alone is not successful.
Lasch et al. (Tue,) studied this question.