ABSTRACT
We evaluated the seroprevalence of measles antibody and response to measles reimmunization in 590 previously vaccinated adolescents and young adults; 263 were seronegative. To differentiate between primary and secondary vaccine failure, anti-measles IgM and IgG titres were assessed again 2-4 weeks after revaccination in 144 (105 seronegative, 39 seropositive) individuals: 75 seronegative participants responded to revaccination anamnestically (P < 0.001) and developed immunity, 11 also showed IgM response (probably primary vaccine failure); 38 seropositive participants remained seroprotected without significant increase in antibody titre (P = 0.577). Primary vaccine failure was 4.7%; secondary vaccine failure was 27.1%. After revaccination, 87.3% were seroprotected.
Subject(s)
Immunization, Secondary/methods , Mass Vaccination/methods , Measles Vaccine/immunology , Measles/epidemiology , Measles/prevention & control , Adolescent , Adult , Aftercare , Antibodies, Viral/blood , Enzyme-Linked Immunosorbent Assay , Female , Health Services Needs and Demand , Humans , Immunization Schedule , Immunoglobulin G/blood , Immunoglobulin M/blood , Iran/epidemiology , Male , Mass Screening/methods , Measles/blood , Measles/immunology , Measles virus/immunology , Population Surveillance , Seroepidemiologic Studies , Treatment FailureABSTRACT
We evaluated the seroprevalence of measles antibody and response to measles re-immunization in 590 previously vaccinated adolescents and young adults; 263 were seronegative. To differentiate between primary and secondary vaccine failure, anti- measles IgM and IgG titres were assessed again 2- 4 weeks after revaccination in 144 [105 seronegative, 39 seropositive] individuals: 75 seronegative participants responded to revaccination anamnestically [P < 0.001] and developed immunity 11 also showed IgM response [probably primary vaccine failure immunity]; 38 seropositive participants, remained seroprotected without significant increase in antibody titre [P = 0.577]. Primary vaccine failure was 4.7%; secondary vaccine failure was 27.1%. After revaccination, 87.3% were seroprotected