Evaluation of immunogenicity after first dose of hepatitis B vaccine in newborns with very low birth weight.

OBJECTIVE: Hepatitis-B virus (HBV) infection is an important health problem worldwide. HBV vaccine application varies according to the birth weight and gestational week in the neonatal period. This study aimed to reconsider delaying the administration of the HBV vaccine because the birth weight of newborns was very low. METHODS: The newborns with very low birth weight in the study group were babies weighing less than 2000 g in the postnatal first month and at the time of administering HBV vaccine. Babies born at term from mothers who did not receive an HBV vaccine, had negative hepatitis B surface antibody levels, and were given HBV vaccine at birth were included in the study as a control group. The antibody levels against HBV vaccine were compared between these two groups. RESULTS: The retrospective study included 60 participants (32 men and 28 women) grouped as control first vaccine weight (first vaccine weight was >2000 g, control group, n = 30) and case vaccine weight (first vaccine weight was <2000 g, case group, n = 30). The mean birth weight was 2976 ± 84.8 g and 1054 ± 44.5 g in the control and case groups, respectively. The first vaccine weight was 2030-3780 g and 960-1900 g in the control and case groups, respectively. The mean antibody level was 297.8 ± 76.3IU/mL and 309.7 ± 56.3IU/mL in the <1500 g and >1500 g groups, respectively. No significant difference was found in hepatitis antibody levels between the groups. CONCLUSION: Further studies in larger samples are needed to confirm the efficacy and efficiency of postponement of hepatitis B vaccination in babies with a birth weight of <2000 g.