RESUMEN
The immune response to diphtheria and tetanus toxoid components of a combined diphtheria tetanus whole-cell pertussis/enhanced inactivated poliovirus (DTwP/eIPV) vaccine, administered in a three-dose schedule to infants at 2, 3 1/2 and 10 months of age and followed by a booster at the age of 8 years, was compared with the immune profile of a group of children at the same ages given the customary DTwP vaccine schedule at 2, 4, 6, and 12 months of age and a booster at the age of 8. Diphtheria- and tetanus-antitoxin titers were measured in parallel enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA). After the reinforcing dose given at 10 months of age, diphtheria antitoxin concentrations of > or = 0.01 IU/ml were found in 100% of infants in the study group, 91.7% of whom reached a titer of > or = 0.1 IU/ml and a geometric mean titer (GMT) of 0.40 and 0.93 IU/ml in ELISA and RIA, respectively. At 3 and 6 years of age, diphtheria antitoxin values of > or = 0.01 IU/ml were detected in 100 and 94% of children with GMT of 0.043 and 0.024 IU/ml, respectively. Seropositivity and GMT values indicative of protection were measured by both ELISA and RIA after the booster at the age of 8 years. Similar results were found in the control group, although the GMT tended to be higher. A good correlation between results obtained by ELISA vs. RIA was evident throughout. Priming at 2 and 3 1/2 months with diphtheria and tetanus antitoxin, as a component of a DTwP program, and reinforcing 6 months later induced an immune response indicative of protection against the diseases, which persisted up to the age of the booster recommended at school entry.
Asunto(s)
Antitoxina Diftérica/inmunología , Vacuna contra Difteria, Tétanos y Tos Ferina/inmunología , Esquemas de Inmunización , Vacuna Antipolio de Virus Inactivados/inmunología , Antitoxina Tetánica/inmunología , Niño , Estudios de Cohortes , Vacuna contra Difteria y Tétanos/administración & dosificación , Vacuna contra Difteria, Tétanos y Tos Ferina/administración & dosificación , Ensayo de Inmunoadsorción Enzimática , Estudios de Seguimiento , Humanos , Inmunización Secundaria , Lactante , Israel , Vacuna Antipolio de Virus Inactivados/administración & dosificación , Vacuna Antipolio Oral/administración & dosificación , RadioinmunoensayoRESUMEN
An outbreak of 15 cases of paralytic poliomyelitis caused by type 1 poliovirus between July and October, 1988, prompted mass vaccination of the whole Israeli population under the age of 40 years. The focus of the outbreak (12 cases) was the Hadera subdistrict, one of two subdistricts where enhanced inactivated poliovaccine (eIPV) had been the only poliovaccine used for infants since 1982. 9 of the 15 victims were 15 years or older, and 9 had previously been immunised with at least three doses of oral poliovaccine (OPV). The authors are divided in their interpretation of the findings. One group considered that the likely causative factors were the greater susceptibility of young adults previously vaccinated with OPV as well as transmission of wild poliovirus to susceptible people by children with low gut immunity against poliovirus after vaccination with eIPV; they concluded that a vaccination programme combining eIPV with OPV is the best option for Israel in future. The other group believed the causative factors were exposure to contaminated sewage or close social contact within the epidemic foci, the presence of an epidemic strain differing from the wild Mahoney and Sabin type 1 vaccine strains, and the lower seropositivity rates and geometric mean titres of neutralising antibodies to the epidemic than to vaccine strains; they believe that eIPV is the means to achieve effective control of poliomyelitis in Israel.