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Trials of intradermal hepatitis B vaccines in Gambian children
Insights
Intradermal hepatitis B virus (HBV) vaccination in Gambian children showed poor antibody responses with standard doses. However, a higher dose (4 micrograms) delivered intradermally via jet gun achieved excellent antibody levels.
Area of Science:
- Immunology
- Vaccinology
- Public Health
Background:
- Hepatitis B virus (HBV) infection is a significant global health concern.
- Effective HBV vaccination strategies are crucial for preventing chronic infection and its sequelae.
- Previous studies explored various HBV vaccine administration routes and dosages.
Purpose of the Study:
- To evaluate the immunogenicity of intradermal hepatitis B virus (HBV) vaccines in Gambian children.
- To compare different intradermal vaccination regimens with intramuscular administration.
- To assess the efficacy of a novel jet gun delivery system for intradermal HBV vaccination.
Main Methods:
- Three trials involving Gambian children were conducted.
- Trial 1: Neonates received 1 microgram (mcg) HBV vaccine intradermally with BCG, followed by two more 1 mcg doses.
- Trial 2: Young children received either two 2 mcg intradermal doses after a 20 mcg intramuscular dose, or three 2 mcg intradermal doses.
- Trial 3: 20 young children received 4 mcg HBV vaccine intradermally via a jet gun.
Main Results:
- Trial 1 showed a failure in antibody response in 19 of 32 subjects (<10 m.i.u./ml).
- Trial 2 regimens yielded significantly lower geometric mean antibody responses and higher vaccine failure rates compared to intramuscular controls.
- Trial 3 demonstrated a good HBV surface antibody response (>100 m.i.u./ml) in all subjects receiving 4 mcg intradermally via jet gun.
Conclusions:
- Standard-dose intradermal HBV vaccination in Gambian children is largely ineffective.
- Higher-dose intradermal vaccination (4 mcg) using a jet gun shows promise for inducing robust antibody responses.
- Further research is needed to optimize intradermal HBV vaccine delivery and dosage for effective immunization programs.
Abstract:
Three trials of intradermal hepatitis B virus (HBV) vaccines were made in Gambian children. In the first trial HBV vaccine (1 microgram) was given to neonates in the same syringe with BCG followed by two further does of 1.0 microgram of intradermal HBV vaccine. The trial was a failure, for 19 of 32 subjects had an HBV surface antibody response of less than 10 m.i.u./ml. In the second trial in young children two different regimes were used: two doses of 2 micrograms HBV vaccine were given intradermally after a 20 micrograms intramuscular dose or three doses of 2 micrograms were given intradermally. In both cases geometric mean antibody responses were significantly lower than in the control group who were given 20 micrograms HBV intramuscularly followed by two 10 micrograms doses intramuscularly. Vaccine failures, defined as the presence of HBV surface antigen or core antibody or absence of surface antibody, were also significantly higher in the intradermal groups. In the third trial 4 micrograms of vaccine were given intradermally to 20 young children with a multiple orifice head fired by a jet gun: all had a good HBV surface antibody response of greater than 100 m.i.u./ml of serum.