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Low dose hepatitis B vaccination in children: benefit of low dose boosters
A Milne1, C D Moyes, M Dimitrakakis
1Hepatitis Research Unit, Whakatane Hospital, New Zealand.
Insights
A low-dose hepatitis B vaccine (H-B-Vax) regimen proved highly effective in children. Four doses of 8 micrograms elicited a strong immune response, comparable to higher doses.
Area of Science:
- Pediatrics
- Immunology
- Vaccinology
Background:
- Hepatitis B virus (HBV) infection poses a significant global health risk.
- Effective vaccination strategies are crucial for preventing HBV transmission, especially in pediatric populations.
- Optimizing vaccine dosage can improve cost-effectiveness and accessibility.
Purpose of the Study:
- To evaluate the immunogenicity of a low-dose, four-dose hepatitis B vaccine (H-B-Vax) regimen in children.
- To compare the immune response to the low-dose regimen with standard higher-dose schedules.
- To determine the appropriateness of a reduced vaccine dose for pediatric HBV immunization.
Main Methods:
- Fifty-eight children aged 5-12 years received three 2-microgram doses of H-B-Vax at 0, 1, and 6 months.
- A booster dose of 2 micrograms was administered 12 months after the third dose.
- Immune response was assessed two weeks post-booster by measuring antibody to hepatitis B surface antigen (anti-HBs) via radioimmunoassay.
Main Results:
- Fifty-seven of 58 children (98.3%) demonstrated positivity for anti-HBs.
- The immune response was anamnestic in 56 of 57 responders.
- The geometric mean titer of anti-HBs increased significantly from 106 IU/L to 15,759 IU/L post-booster, exceeding responses in adults and children on higher-dose schedules.
Conclusions:
- An 8-microgram, four-dose H-B-Vax regimen is highly immunogenic in children aged 5-12 years.
- This low-dose strategy is as effective as the recommended higher-dose schedule (30 micrograms).
- The findings support the use of a low-dose vaccination strategy for the expensive H-B-Vax vaccine in children.
Abstract:
Fifty eight children aged 5-12 years (mean 9.3 years) who had received three x 2 micrograms of Merck Sharp and Dohme (MSD) H-B-Vax intramuscularly at time 0, 1, 6 months were given a further 2 micrograms dose 12 months after dose 3 and tested for immune response two weeks later. Fifty seven of 58 children were positive for antibody to hepatitis B surface antigen (anti-HBs) when tested by radioimmunoassay. In 56 of the 57, the response was anamnestic in nature. The geometric mean titre of anti-HBs rose from 106 IU/L before, to 15,759 IU/L after the booster dose. The latter figure was greater than that obtained in 20 adults given three x 20 micrograms of the same vaccine and also greater than that reported in children given three x 10 micrograms of MSD H-B-Vax. This study demonstrates that 8 micrograms of H-B-Vax given as four doses is at least as immunogenic in children as 30 micrograms of the same vaccine given as recommended and that the low dose strategy is appropriate for this expensive vaccine.