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Hepatitis B vaccine boosters: further studies in children
Insights
Reduced dose hepatitis B vaccine boosters provide sustained protection in children. Even poor responders achieved protective antibody levels, confirming vaccine efficacy for at least three years.
Area of Science:
- Immunology
- Vaccinology
- Public Health
Background:
- Hepatitis B vaccination is crucial for preventing infection.
- Assessing long-term immunogenicity of recombinant yeast-derived hepatitis B vaccine (YDV) boosters is important.
- Understanding immune response in different pediatric populations is key.
Purpose of the Study:
- To evaluate the immunogenicity and protective efficacy of reduced-dose YDV boosters in children.
- To assess the immune response in both unselected children and those with suboptimal primary response.
- To confirm the duration of protection offered by the vaccine.
Main Methods:
- Two groups of children received YDV boosters 30-34 months post-primary immunization with plasma-derived vaccine (PDV).
- Geometric Mean Titre (GMT) and anti-HBs levels were measured before and after booster doses.
- Children were categorized as unselected or poor responders to primary vaccination.
Main Results:
- In unselected children, GMT increased from 387 to 8346 IU/L, with 100% protection.
- In poor responders, GMT rose from 14.6 to 325 IU/L, with 95% achieving protective anti-HBs levels (>10 IU/L).
- All children demonstrated protective antibody levels post-booster.
Conclusions:
- Reduced dose YDV boosters are highly effective in children, including poor responders.
- The hepatitis B vaccine provides protection for the majority of children for at least three years.
- Supports the continued use of YDV in preschool immunization programs.
Abstract:
Two groups of children were given reduced dose boosters with Merck Sharp and Dohme (MSD) recombinant DNa, yeast derived hepatitis B vaccine (YDV), 30 and 34 months respectively after primary immunisation with MSD plasma derived vaccine (PDV). In the first group of unselected children the geometric mean titre (GMT) rose from 387 to 8346 IU/L, with all children protected. The second group were selected as the poorest responders to their primary course of vaccine. The booster raised the GMT from 14.6 to 325 IU/L, with 95% having protective levels of anti-HBs (greater than 10 IU/L). This study confirms that the vaccine used by the New Zealand Department of Health for the hepatitis B immunisation programme in preschoolers, will provide protection for the great majority of children for at least three years.