RESUMEN
Purpose: This study was designed to evaluate the immunogenicity of hepatitis B vaccine in infants of rural and urban Pakistan and to find out the vaccine efficacy. Methods: A sample of 400 subjects was taken by simple random method from the rural and urban areas (200 from Rural and 200 from urban areas) of Rawalpindi District Pakistan. The serum samples were analyzed by Enzyme Linked Immunosorbant assay (ELISA) for the quantitative determination of antiHBs antibodies. Results: As 88 (22%) infants out of the total 400 were found to be seropositive at baseline. The post vaccination results showed that about 15 (7.53%) of infants had inadequate levels of antibodies (i.e. <10 IU/L). Overall 92.46% infants showed a positive response to the vaccine. The females showed higher titers of antiHBs against vaccination as compared to that of males. Infants of urban areas showed higher titers as compared to that of rural areas. Conclusion: Our results reinforces that the Hepatitis B vaccine has a good tolerability and is highly immunogenic among infants. It is recommended that serosurvey of HBsAg and vaccine coverage at country level should be done.