Detection of IgG antibody affinity in suspected cases of measles and rubella in Beijing / 中华微生物学和免疫学杂志

ABSTRACT

Objective:To investigate the causes of immune failure in the population with high vaccination rate of measles and rubella vaccine in Beijing by detecting the IgG antibody affinity in suspected cases of measles and rubella.Methods:Serum samples of 276 suspected cases of measles and rubella were tested for IgM and IgG antibodies by enzyme-linked immunosorbent assay (ELISA). The affinity of IgG antibody was detected, and the relative affinity index was calculated.Results:Among the 276 suspected cases, 104 were measles and 108 were rubella. Six measles cases had vaccination history and were caused by primary immunization failure ( n=3) and secondary immunization failure ( n=3). Twelve rubella cases had vaccination history and were due to primary immunization failure ( n=4) and secondary immunization failure ( n=8). Specific high-affinity antibodies were detected in nine measles cases and seven rubella cases without vaccination history, which indicated that these cases were reinfected. In the cases without measles or rubella, other pathogenic infections including mixed infections were detected, which were mainly caused by EB virus. Conclusions:Both primary and secondary immunization failure occurred in the population with immunization history. Reinfection was found in the patients who had not received vaccination against measles or rubella. Other pathogenic infections were existed among the cases without measles or rubella. Thus, misdiagnosis was responsible for the increased proportion of measles and rubella patients with immunization history in suspected cases in recent years. Full-course vaccination was conducive to produce high-affinity antibodies against measles and rubella. A supplementary vaccination campaign should be launched to consolidate the immune barrier against measles and rubella in key population or high-risk population, aiming to block the circulation of measles virus and achieve the goal of eliminating measles.