THE ASSOCIATION OF AGE AND NUTRITIONAL STATUS WITH SEROCOVERSIOIN TO ORAL POLIOVIRUS VACCINE (OPV) IN BASRAH, IRAQ

A seroepidemiological study was carried out in Basrah, southern Iraq from November 1997 until the end of April 1998. Blood samples were collected from 3 sources; Basrah Maternity and Child Hospital, the primary health care centers in Al-Zubair and Abu-AlKhasib. The relevant information’s were obtained from mothers through interview and/or vaccination cards. An Enzyme linked Immunosorbent assay (ELISA) was used for the detection of poliovirus IgG antibodies. Poliovirus antibodies were found in 92.85% with almost full seroconversion among children above 2 years of age, while seronegative cases were present among infant’s children below the age of two years and those with old vaccination history and not boosted with additional booster doses. Malnourished children have relatively lower levels of antibody titer than well nourished children. Number of vaccine doses given to the child have a significant effect on antibody prevalence where high levels of immunity were found in children who received 5 doses or more while seronegative cases were detected among children who had been given 4 doses or less, There were relatively higher seropositivity among children who received an extra doses during the National Immunization Days (NID) than among those who did not receive extra dose(s).The antibody levels in the blood is partially affected by age and the number of vaccine doses given to the child where the proportion of samples with low antibody levels decreased as the age and number of vaccine doses increases. There was clear evidence for the overtime antibody losses among the