Booster Vaccination in Infancy Reduces the Incidence of Occult HBV Infection in Maternal HBsAg-positive Children

Background and Aims: Occult HBV infection (OBI) in chil-dren has proven to be associated with their immune re-sponse to hepatitis B vaccine (HepB). This study aimed to investigate the effect of a booster HepB on OBI, which is rarely investigated. Methods: This study enrolled 236 ma-ternal HBsAg-positive children who were followed up annu-ally until 8 years of age and were hepatitis B surface antigen (HBsAg) negative. Of those 100 received a booster HepB be-tween 1 and 3 years of age (booster group), and 136 were never boosted (non-booster group). Serial follow-up data of children and baseline data of their mothers were collected and between-group differences were analyzed. Results: The incidence of OBI varied dynamically during follow-up, with 37.14% (78/210), 19.09% (42/220), 20.85% (44/211), 31.61% (61/193), 8.65% (18/208) and 12.71% (30/236) at 7 months, 1, 2, 3, 4, and 8 years of age. At 8 years of age, the negative conversion rate of HBV DNA in the booster group was significantly higher than that in non-booster group [57.89% (11/19) vs. 30.51% (18/59), p=0.032]. For chil-dren without OBI at 7 months old, the incidence of OBI in booster group was significantly lower than that in non-boost-er group [25.64% (10/39) vs. 67.74% (63/93), p<0.001]. Conclusions: The incidence of OBI in maternal HBsAg-positive children was high, serum HBV DNA in children with OBI was intermittently positive at low levels, and a booster HepB in infancy reduced the incidence of OBI in children with HBsAg-positive mothers.

Vaginal Delivery and Breastfeeding Benefit Infant Immune Response to Hepatitis B Vaccine:A Prospective Cohort Study

Background and Aims:Natural vaginal delivery and breastfeeding favor the development of a strong immune system in infants,and the immune response of infants to vaccines is closely related to their immune system.This large prospective cohort study aimed to explore the effects of delivery and feeding mode on infant’s immune response to hepatitis B vaccine(HepB).Methods:A total of 1,254 infants who completed the whole course of HepB immunization and whose parents were both HBsAg negative were enrolled from infants born in Jinchang City during 2018-2019 by cluster sampling method.Results:Twenty(1.59%)of the 1,254 infants were nonresponders to HepB.Among the other 1,234 infants,10.05%(124/1,234),81.69%(1,008/1,234)and 8.27%(102/1,234)of infants had low,medium,and high responses to HepB,respectively.Logistic regression analysis showed that cesarean section(OR:8.58,95%CI:3.11-23.65,p<0.001)and birth weight<3.18 kg(OR:5.58,95%CI:1.89-16.51,p=0.002)were independent risk factors for infant nonresponse to HepB,and cesarean section(OR:7.63,95%CI:4.64-12.56,p<0.001),formula feeding(OR:4.91,95%CI:1.47-16.45,p=0.001),maternal antiHBs negativity(OR:27.2,95%CI:10.67-69.35,p<0.001),paternal non-response history of HepB(OR:7.86,95%CI:2.22-27.82,p=0.014)and birth weight<3.22 kg(OR:4.00,95%CI:2.43-6.59,p<0.001)were independent risk factors for infant low response to HepB.In cases where birth weight and genetic factors are unmodifiable and maternal anti-HBs effects are controversial,it makes sense to enhance infant response by changing delivery and feeding patterns.Conclusions:Natural vaginal delivery and breastfeeding are beneficial to the infant’s immune response to HepB.