ABSTRACT
The antigenic capacity of one and of two doses of Lederle-Cox oral trivalent poliomyelitis vaccine was studied in a group of children aged from 6 months to 5 years living in Huitzilac (Morelos) and of Tlaxcala (Tlaxcala) in Mexico
The serologic conversion rate obtained with one dose in both villages was 32.3 per cent, 25.1 per cent, and 72.8 per cent for Types 1, 2, and 3, respectively. In a group of children in Tlaxcala the conversion percentage with two doses was 55.7 per cent for Type 1, 43.8 per cent for Type 2, and 89.3 per cent for Type 3. The Markham seronegativity index was 75.7 per cent before the vaccination and 28.6 per cent after the administration of the two doses. It should be noted that the second dose produced a higher conversion percentage than the first, especially in triple-negative children
Although in general it is pointed out that the component of Type 2 of this vaccine is the least antigenic - as was confirmed by this study - that of Type 1 of the lot tested was also defective. The reasons for the low potency of the lot used are discussed. Mention is also made of the interference of the natural enteric viruses with the vaccine strains. The degree of dissemination of the latter to susceptible contacts was estimated to be around 8 per cent
During the study no cases of paralytic poliomyelitis or pathological manifestation attributable to the vaccine were observed(AU)
Subject(s)
Poliovirus Vaccine, Oral/immunology , Poliomyelitis/immunology , Poliovirus/isolation & purification , Immunologic Surveillance , MexicoSubject(s)
Rabies/diagnosis , Rabies/history , Chiroptera , Rabies Vaccines/therapy , Health Surveys , MexicoABSTRACT
The antigenic capacity of one and of two doses of Lederle-Cox oral trivalent poliomyelitis vaccine was studied in a group of children aged from 6 months to 5 years living in Huitzilac (Morelos) and of Tlaxcala (Tlaxcala) in Mexico
The serologic conversion rate obtained with one dose in both villages was 32.3 per cent, 25.1 per cent, and 72.8 per cent for Types 1, 2, and 3, respectively. In a group of children in Tlaxcala the conversion percentage with two doses was 55.7 per cent for Type 1, 43.8 per cent for Type 2, and 89.3 per cent for Type 3. The Markham seronegativity index was 75.7 per cent before the vaccination and 28.6 per cent after the administration of the two doses. It should be noted that the second dose produced a higher conversion percentage than the first, especially in triple-negative children
Although in general it is pointed out that the component of Type 2 of this vaccine is the least antigenic - as was confirmed by this study - that of Type 1 of the lot tested was also defective. The reasons for the low potency of the lot used are discussed. Mention is also made of the interference of the natural enteric viruses with the vaccine strains. The degree of dissemination of the latter to susceptible contacts was estimated to be around 8 per cent
During the study no cases of paralytic poliomyelitis or pathological manifestation attributable to the vaccine were observed(AU)
Subject(s)
Poliovirus Vaccine, Oral , Poliomyelitis , Poliovirus , Immunologic Surveillance , MexicoABSTRACT
This article contains information on the incidence of arthropod-borne encephalitic diseases caused by EE, EEO, EEV, ESL and Ilheus arboviruses in the folloing Mexican states: Sonora, Tamaulipas, Nayarit, Jalisco, Federal District, Morelos, Veracruz, Tabasco, Campeche, Yucatan and Quintana Roo
Serological surveys in persons between the ages of 5 and 60 years show that the overall infection rate in these regions has remained low
There have been no oubreaks of encephalitis with the exception of that which occurred in Campeche in 1962 and affected 13 persons. The finding of EEV in Campeche, subsequently confirmed by isolation of the virus, is of epidemiological interest not only for Mexico but for other countries since this virus had heretofore not been identified north of Panama
Since infection rates are low, the potential hazard presented in the areas in which there are virus vectors and reservoirs by the great number of susceptible persons in the population, namely ...(AU)
In Xochimilco and Mexico City, D.F., which are 2,240 meters above sea level no cases of human encephalitis caused by the viruses covered by the survey have been encountered nor have any human cases due to ESL and Ilheus virus been reported in Coatetelco, Morelos, which lies on the Central Meseta at an altitude slightly below that of the Federal District. However, vectors and reservoirs of these viruses do exist in these regions
