Dynamics of maternally transferred antibodies against measles, mumps and rubella in infants in Sri Lanka.

Abstract

BACKGROUND\nDetermining dynamics of maternally transferred antibodies against measles, mumps and rubella infections in infants is important for making evidence -based policy decisions for the timing of vaccination.\n\n\nMETHOD\nSerum immunoglobulin G (IgG) levels, developed against measles, mumps and rubella were assessed using commercial ELISA kits, in mother-newborn pairs (n\u2009=\u2009294) and 6-12 months old infants (n\u2009=\u2009280) recruited from Colombo District, Sri Lanka. Antibody levels of mothers & their newborns with respect to gender and parity were assessed. Antibody levels and the protection conferred were assessed in a sample of infants who completed 6-12 months of age in relation to their age and gender. Antibody levels were compared between different age and gender groups using Mann-Whitney U test and correlations of antibody titers was done using Spearman Correlation test.\n\n\nRESULTS\nThe prevalence of sero-positivity for measles, mumps and rubella were 91.5%, 89 % and 88% in mothers and 95 %, 91.5 % and 93% in their newborns respectively and the newborns had mean IgG levels exceeded that of maternal levels (p\u2009<\u20090.001). Mothers with natural infections had higher antibody levels compared to vaccinated mothers which resulted in a higher level of maternal transfer. All the infants who were 9-10 months or older, 10-11 months or older, or who were 11-12 months old were sero-negative to measles, rubella and mumps respectively.\n\n\nCONCLUSIONS\nMaternal transfer of antibodies to newborns is efficient and renders protection till infants are 6-7 months old in case of mumps and rubella and till 7-8 months in case of measles. Hence the infants remain vulnerable to infections before the first dose of MMR vaccine.