Session Title: VACCINE AND PREVENTION
MEASLES ANTIBODIES IN NEWBORNS IN RELATION TO MATERNAL IMMUNIZATION STATUS
M. Machaira, C.-N. Makrinioti, V. Papaevangelou
Second Department of Paediatrics, University of Athens, Medical School, 'P.& A. Kyriakou' Children's Hospital, Athens, Greece
Background and aims: The protection provided by transplacentally transmitted maternal antibodies against measles is changing since most women are vaccinated, age of primigravida is increasing and boosting effect of circulating natural infections is decreasing. This study aims to measure passive transmission of measles maternal antibodies to newborns, in relation to mother's medical history of natural infection or vaccination status against measles.
Methods: Maternal and neonatal serum samples were collected 2-3 days after delivery. Measles natural infection history or vaccination status was noted. IgG antibody levels against measles were detected by Measles IgG Capture Enzyme Immunoassay (Microimmune Ltd, UK).
Results: One hundred and eight mothers (16 to 38 years old) and their neonates were included in this study. Most women (99/108, 91.7%) had been immunized against measles, only 5 mothers had history of past natural infection and 4 mothers had no knowledge of their immunization status. Most mother-newborn pairs had concordant results (98 positive and 7 negative) whereas 3 neonates of mothers with detectable IgG antibodies were found seronegative. Ten newborns born to immunized women (10.1%) had undetectable measles IgG antibodies.
Conclusions: In this cohort of children, 1 in 10 neonates born to immunized mothers had undetectable measles antibodies at birth. Prospective follow up of this cohort at 3 and 6 months of age, will further support recently accumulating data suggesting that infants' window of susceptibility is increasing and earlier immunization against measles may be necessary.