Maternal Measles Antibodies Wane by 6 Months of Age
Infants of naturally immune moms protected longer than infants of vaccinated mothers
WEDNESDAY, May 19 (HealthDay News) -- Maternal measles antibodies wane quickly after birth, with nearly all babies losing maternal antibody protection by age 6 months, according to research published online May 18 in the BMJ.
Elke Leuridan, of the University of Antwerp, Belgium, and colleagues conducted a prospective study of 207 woman-infant pairs, divided into a naturally immune group of mothers and a vaccinated group of mothers. The main outcome measures were measles IgG antibodies measured at multiple time periods during late pregnancy through the infants' first 12 months of life.
The researchers found that overall, vaccinated women had significantly fewer measles antibodies than naturally immune women, and there was high correlation between maternal antibody levels and infant antibodies at birth. Infants of vaccinated women had significantly lower maternal antibody levels than did infants of naturally immune women throughout the study period. For infants of vaccinated women, maternal antibodies remained detectable until a median of 0.97 months, with 99 percent lacking maternal antibodies by 6 months of age. Infants of naturally immune mothers retained maternal antibodies for a median of 3.78 months, and 95 percent had lost maternal antibodies by age 6 months.
"If future studies could further show that measles vaccines can be offered at an earlier age (for example, at 9 months or even earlier), policymakers could consider, given our data, moving forward the routine measles vaccination program. For the moment, vaccination at a young age should be considered in case of a situation of early exposure (such as an outbreak or contact with siblings with measles)," the authors write.
The study was partly funded by GlaxoSmithKline Belgium.