Determination of the immune response type in measles patients of different ages from a high-incidence area

Abstract

According to the WHO data, the incidence of measles is now in the cyclic increase phase. The non-vaccinated subjects, like as persons who have previously received one or two doses of measles vaccine are involved in the epidemic process. The purpose of our study was to determine the immunological pattern in the groups of measles patients of different age in areas with high incidence of infection. To determine the immune response type in measles patients, qualitative and quantitative indices of IgM and IgG were used, detected by the following ELISA test-systems: VectoMeasles-IgM (JSC “Vector-Best”, Russia); Anti-Measles Viruses ELISA (IgG) and Avidity Anti-Measles Viruses ELISA IgG (Euroimmun, Germany). The serological study of 1893 patient allowed to determine the primary and secondary types of immune response. In 72.64% of the patients with primary immune response, the serum samples contained low-avidity IgG at a concentration of 0.45 (0.22- 0.74) IU/mL. In the group with a secondary immune response, high-avidity antibodies were detected at a concentration of 24.28 (21.59-27.4) IU/mL. The antibody levels in secondary type of response was 54-fold higher than IgG values in the first group (p 0.05). In the group with primary immune response, the ratio of children ( 1 to 14 years) and adults (18 to 70 years old) was almost the same (49.6% and 47.56%). Appropriate values for children and adult cohorts with a secondary immune response were 2.12% and 96.53%, respectively (p 0.05). Among 46 teenagers (15-17 years old), 84.8% responded with a primary immune response to the measles virus. Thus, in the area with high-incidence of measles among patients of different age, the primary-type immune response was determined in 72.64%, and secondary-type, in 27.36%. We have found that in the patients with a secondary type of immune response group, the proportion of children and teenagers was 27.8 times lower than among adults, thus indicating to high efficiency of vaccination in pediatric population. At the same time, the results of studies among measles patients with primary-type immune response, both children and adults, suggest some “gaps” in the vaccine prevention program.