Measles Vaccination Immunogenicity and Association with Caste in Chandigarh, India

Abstract

ABSTRACT. Measles affects those of lower socioeconomic status disproportionately. This study evaluated the impact of measles vaccination on antibody titers 3 months after vaccination across different socioeconomic groups, with a focus on caste. In total, 169 infants in Chandigarh, India, had serum samples collected immediately prior to vaccination at 9 months of age and 3 months later. Overall, 126 infants (76%) were seropositive (antibody titers > 12 mIU/mL), 26 (16%) were borderline (8–12 mIU/mL), and 14 (8%) were seronegative (< 8 mIU/mL). Seropositivity (versus borderline/seronegative infants) was 0.78 times as high among individuals from the historically marginalized scheduled castes/scheduled tribes compared with the others caste grouping (95% CI, 0.62–0.98). Antibody response was not tied to anthropometric measures but was attenuated among scheduled castes/scheduled tribes with higher incomes. This study provides observational evidence that social structures can be associated with individual immune responses.