Seroprevalence of Transplacentally acquired Measles antibodies in unvaccinated infants at nine months of age and its relation to the feeding practices.

Background: In recent years Pakistan has faced frequent measles outbreaks killing hundreds of children despite the availability of vaccine for decades. This study was undertaken to determine the persistence of maternal transferred measles antibody levels in infants before measles vaccination with relation to their feeding practices.

Methods: A cross sectional study was conducted at district Islamabad over 1 year between 1st October 2013 to 30th Sept. 2016. Any infant less than 9 months of age, not suffering from an acute or debilitating illness and not vaccinated was enrolled in the study. After taking written informed consent from parents / guardians, information was collected on a pretested questionnaire. About 3 cc venous blood was taken to quantify any measles IgG antibodies. Data was analyzed by using Epi Info 7.2 version.

Results: Three hundred eighty-four infants were enrolled and were divided into three age groups, 1-90, 91-180 and 181-270 days age groups. Mean age of infants was 4.4 months ±3.2 SD. Male to female ratio was 1.2:1. A level of maternal measles IgG antibodies ≥12 U/ml was taken as protective. Of total 384 infants, 91(24%) had protective measles antibody titters (> 12 U/ml). and 65 (73%) of them were on breast milk. Highest antibody levels were found in 1-90 days age group. Analysis showed that 181-270 days aged infants had 3.1875 more odds of having unprotected/ low levels of antibodies against measles than children aged less than 180 days. Age group < 180 days found to be statistically significant with protective IgG levels (OR: 3.1875, P value: < 0.000063).

Conclusion: Measles protective antibodies were found in infants < 180 days age group. Breast feeding provides early protection against measles. Levels drop down to low levels immediately after birth and then after 06 months. It is, therefore, recommended that measles vaccination should be considered for administration at 6 months or even earlier if measles immunity is desired.