Infant HBV Research Articles

A non-randomized vaccine effectiveness trial of accelerated infant hepatitis B immunization schedules with a first dose at birth or age 6 weeks in Côte d’Ivoire

Most African countries do not initiate hepatitis B vaccination at birth. We conducted a non-randomized controlled trial comparing hepatitis B vaccination given at age 0, 6, and 14 weeks versus the current Côte d'Ivoire schedule of 6, 10, and 14 weeks. Pregnant women were enrolled at four health centers in Abidjan. At age 9 months, 0.5% of infants in both the birth and 6-week cohorts were positive for HBsAg and all were born to HBeAg-positive women. Among infants of HBeAg-positive mothers, 9 of 24 (37.5%) in the birth cohort and 10 of 17 (58.8%) in the 6-week cohort were HBsAg positive (adjusted OR, 2.7; 95% CI: 0.7-11.0). While both vaccine schedules prevented most cases of infant HBV transmission, both also had high failure rates among infants of HBeAg-positive mothers. African infants may benefit from a birth dose but additional studies are needed to verify this hypothesis.

DTPa‐HBV‐IPV vaccine for primary vaccination of infants

Combined vaccines have an increasingly important role to play in delivering these antigens acceptably. We describe the immunogenicity and reactogenicity of a combined DTPa-HBV-IPV vaccine (diphtheria, tetanus, acellular pertussis, hepatitis B, inactivated poliovirus (DTPa-HBV-IPV: Infanrix penta) ) when administered for the primary vaccination of infants resulting from a study where the primary objective was to demonstrate non-inferiority of the immune response induced by DTPa-HBV-IPV using an industrial-scale IPV production process. Three hundred and fourteen infants received primary immunisation with DTPa-HBV-IPV at 2, 4 and 6 months of age. Routine Haemophilus influenzae immunisation was performed at 2 and 4 months of age at a separate injection site. Blood samples were taken at 2 and 7 months of age. Reactogenicity was assessed using diary cards for 7 days after each dose. One month after the primary course, at least 98.9% of subjects achieved seroprotective antibody concentrations/titres against diphtheria, tetanus, hepatitis-B and polio types 1, 2 and 3. More than 97% had a vaccine response to pertussis antigens. The incidence of local injection site reactions after DTPa-HBV-IPV was similar to that for the Haemophilus influenzae vaccine site. General reactions of Grade 3 intensity were uncommon. The DTPa-HBV-IPV vaccine is a new combination of vaccines previously available separately, with established effectiveness and safety profiles. Combined vaccines reduce storage requirements and minimise the number of injections required, thereby reducing distress for infants and parents. DTPa-HBV-IPV was immunogenic with an acceptable safety profile and could replace separate administration of DTPa, HBV and IPV vaccines in infants.

Distribution of Viral Hepatitis in Indigenous Populations of North America and the Circumpolar Arctic

The burden of viral hepatitis among indigenous populations of the United States, Canada and Greenland is greater than in non-indigenous populations. In particular, throughout the circumpolar Arctic regions, chronic hepatitis B infection is highly prevalent, although incidence rates have declined considerably in certain regions due to infant HBV vaccination. Unique HBV (sub)genotypes having distinct clinical outcomes and distribution patterns are also observed within this region. In conjunction with hepatitis B infection, hepatitis delta infection is also apparent within North American indigenous peoples, particularly with outbreaks in Greenlandic Inuit communities. Incidence rates for hepatitis C infection are higher for indigenous populations within the United States and Canada; however, some hepatitis C antibody-positive indigenous patients are more likely to be HCV RNA-negative compared to non-indigenous patients. Thus, an increased understanding of the epidemiology, clinical consequences and pathogenicity of viral hepatitis affecting the indigenous populations will help to address and balance the burden of infection.

Prevention of hepatitis B infection in infants born to hepatitis B carrier mothers: low dosage vaccination

Two groups of newborn infants born to HBeAg positive carrier mothers were given HBIG (200 IU) immediately after birth. Subsequently, at age 2 days and at 1, 2 and 12 months, the first group received 5 μg and the second group 2 μg of HBV vaccines. There was no significant difference in the anti-HBs seroconversion rate (SR), and the protective efficacy rate (PER) at the age of 13 months in either group. The SR and PER of group I were 91.7% and 90.18%, and group II were 92.9% and 91.01%, respectively. Although the significant differences were observed in the geometric mean titers of anti-HBs in group I (526.3 mIU/ml) and group II (371.4 mIU/ml), both were above the protective level. The immune responses to the reduced dosage of HBV vaccines are satisfactory in preventing HBV in the newborn infants of HBeAg positive carrier mothers.