Effect of Measles Virus Antibodies from Breast Milk of Nursing Mothers on Seroconversion of Children After Measles Vaccination.

The effects of measles virus (MV) antibodies (abs) in the sera and breast milk of nursing and lactating mothers on sericonversion to measles vaccination was studied. Three hundred and ninty six samples were collected each from sera and breast milk of nursing mothers and corresponding number of finger prick prevaccination sera samples on filter paper from their children were tested for MV abs. Eighty (20.2%) mothers had measles haemagglutination inhibition (HI) abs in their sera and 88(27.2%) had MV HI abs in their breast milk. Eight (2.0%) of the children who had prevaccination MV abs in their sera were all from MV ab negative mothers. Forty-four (37.0%) who came back for post vaccination sera seroconverted while 76 (63.3%) gave a low seroconversion rate of 37.0%. Results showed that MV abs in either sera or breast milk of mothers did not interfer with MV vaccination in their children. The low seroconversion rate obtained was due to low vaccine potency with titers ranging between (log10-1.0 – log10-2.5) TCID/per dose. This was beside other non-specific antiviral substances exhibited virus neutralizing activity.