Regular vaccination against poliomyelitis was started in 1960 with oral polio vaccine (OPV). Since 1992 a trivalent OPV has been administered in five doses within a nationwide vaccination campaign. The immunization coverage varies between 96.8% and 98.2% after 4 OPV doses, reaching 98.0% to 98.9% after the fifth dose. No case of indigenous poliomyelitis has been reported in the Czech Republic since the second half of 1960. In 2001, 3,230 sera were tested for the presence of antibodies against poliovirus of types 1, 2 and 3 using a virus neutralization microassay. The prevalence rates of antibodies vary between 96.0% and 100% for types 1 and 2 and between 95.1% and 100% for type 3, with the exception of the highest age group, in which the prevalence rates of antibodies against poliovirus of all three types are 92.2%.
The goal of this work was to estimate the collective immunity against poliomyelitis among the population of 8 regions and republics of Russia. The rates of the collective immunity against poliomyelitis allow the polio vaccination quality to be estimated and the population protection rate to be simultaneously demonstrated. A total of 8 regions (2138 people) were tested. The antibodies to the polioviruses of 1-3 types were determined against the vaccine Sabin strains in the neutralization test in the RD cell line. As a result, we found that vaccination against poliomyelitis in all observed regions was maintained at the required high level. Thus, the number of people with antibodies to the polio in most regions and age groups approximates or reaches 100%, while GMT is also high. This work demonstrated the necessity of the continuation of vaccination against poliomyelitis and control over collective immunity.
Monitoring of implementation of international programs of poliomyelitis eradication, and measles and rubella elimination in the Republic of Belarus based on results of molecular-epidemiologic studies of 2009 - 2010.
271 viral agents isolated from children with acute flaccid paralysis syndrome, other diseases, healthy children and from sewage water within the framework of poliomyelitis control implementation were identified by serological and molecular methods. Blood sera of 528 patients with fever and rash were examined for the presence of IgM to measles and rubella virus, 418 - for the presence of IgM to parvovirus B19 and parvovirus DNA. Blood sera of 33 pregnant women and 64 children with signs of intrauterine infection were studied for IgM and IgG antibodies to rubella virus. Measles virus was isolated, N-gene sequence and phylogenetic analysis carried out.
The studies performed confirmed that indigenous wild polioviruses in the country do not circulate, imported wild or vaccine-related polioviruses were also not detected. Measles and rubella morbidity in the Republic of Belarus was less than 1 in 1 000 000. 2 cases of rubella (2009) and 1 case of measles (2010) was detected during adequate control level: the rate of detection of patients with fever and rash, in whom measles and rubella diagnosis was excluded by the results of laboratory examination, was more than 2 in 100 000 of the population. The etiologic agent in more than 20% of diseases with fever and rash was parvovirus B19. A single case of measles was caused by genotype D8 virus imported from India.
The data obtained give evidence to conformance of the poliomyelitis, measles, rubella, innate rubella syndrome control implemented in the Republic of Belarus to WHO recommendations; maintenance of status of country as free from poliomyelitis and achievement of main criteria of elimination of both measles and rubella by 2010.
Study the state of collective immunity against poliomyelitis in 7 regions of Russia in the last 3 years.
2579 sera were studied for antibodies against poliomyelitis virus. Antibodies (AT) against 3 types of viruses were determined in neutralization reaction in RD cell culture, the state of collective immunity in the examined individuals was evaluated by the percent of individuals with AT against a type of poliovirus and geometric mean AT titer. The circulation of wild polioviruses was judged by the presence of strain specific AT against wild and vaccine viruses in the examined children (311 sera were studied).
The indicators of collective immunity against poliomyelitis in both select examined regions and select age groups were generally high. The data obtained allow to make a conclusion that the quality of vaccine prophylaxis in the examined regions is good. Introduction of wild poliovirus type 1 from Tajikistan in 2010 caused disease in 7 residents of Russia whereas an epidemic that had affected more than 700 individuals emerged in Tajikistan.
The studies carried out confirmed the necessity to continue qualitative poliomyelitis vaccine prophylaxis in the country despite the lack of circulation of wild polioviruses that can be introduced at any time.