摘要
Objective:To assess levels of HBs Ab amongst infants who received hepatitis B vaccine in the Expanded Program on Immunization in Vietnam.Methods:A cross-sectional study was carried out at 16 community health centers from February 2016 to July 2017.Eligible infants were tested for HBs Ab and HBs Ag.Structured questionnaires were used to collect relevant information about the demographics of the parents/caregivers and their infants after physical examination.Results:A total of 199 eligible infants were selected with a mean age of(17.3±4.5)months.Protective antibody levels with HBs Ab≥10 m IU/m L were detected in 68.3%of infants.Of these,antibody levels from 10 to 99 m IU/m L were 48.5%of those tested and antibody levels≥100 ml U/m L were recorded as 51.5%.No cases were recorded of being infected with hepatitis B virus.The rate of positive HBs Ab level in those who were not wasting and≥18 months old was less than that among those who were<18 months old(OR 0.49,95%CI:0.26-0.92,P<0.05)while the infants with wasting and<18 months were less likely to be positive HBs Ab than those who were not wasting and of the same age group(OR 0.15,95%CI:0.04-0.55,P<0.05).Conclusions:Seroprotection against hepatitis B virus was low in the infants tested(at 68.3%),which suggests that the hepatitis B vaccine should be administered with one additional dose for infants between 12 and 24 months of age,particularly those with wasting.
