RESUMO
Objective To analyze the efficacy of a second dose of measles-mumps-rubella (MMR) vaccine in children aged 6 to 7 years in Xicheng District, Beijing, China in 2016.Methods Serum samples were collected in duplicate from 41 children aged 6 to 7 years before and one month after immunization with a second dose of MMR vaccine.ELISA was performed to detect IgG antibodies against measles, rubella and mumps in serum samples.Results The positive rates of antibodies against measles, rubella and mumps in the 41 children before immunization with a second dose of MMR vaccine were 95.12%, 90.24% and 92.68% and the antibody titers were (825.88±499.91), (53.83±32.48) and (697.83±535.82) IU/ml, respectively.The positive rates of the three antibodies were 100%, 97.56% and 100% after revaccination with MMR vaccine and the antibody titers were (1 102.98±356.77), (95.08±26.88) and (3 383.85±1 903.06) IU/ml.Titers of antibodies against measles, rubella and mumps increased significantly following revaccination (P0.05).Conclusion The second dose immunization of MMR vaccine achieves a high successful rate in children in Xicheng District of Beijing.It would be an effective immunization strategy to protect children from measles, rubella and mumps.