Objective: To study the vaccine-induced measles specific immunoglobulin G (IgG) response in children aged 4-12 years immunized with two doses of measles containing vaccine in infancy.
Methods: This cross-sectional study was done in a tertiary care centre for a period of 18 months from January, 2017. Measles specific IgG levels were assessed using ELISA technique in 80 children of age 4-12 years, [mean (SD) age, 7.5 (2065)] who had received two doses of measles vaccine in infancy. Measles-specific IgG levels >11 NTU were considered protective.
Results: Protective levels of measles specific IgG were found in 86.4%. Significant association was found between negative immune response to measles vaccine and low socioeconomic status (P=0.03), under-nutrition (P=0.001), anemia (P=0.03), lack of exclusive breast feeding till 5 months of age (P=0.007) and higher parity (P=0.002).
Conclusions: Less than one-seventh of children immunized with two doses of measles vaccine in infancy had measles-specific IgG below protective levels at the average age of 7.5 yr. Lack of exclusive breast feeding till 5 months of age, under-nutrition and anemia were the associated factors.