Immunity to hepatitis A and B persists for at least 15 years after immunisation of adolescents with a combined hepatitis A and B vaccine.
The exact duration of antibody persistence to hepatitis A and B and the need for booster dosing following primary immunisation remains undefined. A long-term study was designed to follow antibody persistence and immune memory on an annual basis for up to 15 years following vaccination during adolescence.



Subjects received a combined hepatitis A and B vaccine (Twinrix™, GSK Vaccines, Belgium) at 12-15 years of age, either as 2-dose of the adult formulation or 3-dose of the paediatric formulation. Blood samples were taken every year thereafter to assess antibody persistence and immune memory to hepatitis A and B. Antibodies to hepatitis A virus (anti-HAV) and hepatitis B surface antigen (anti-HBs) were measured at Years 11-15. At Year 15 immune memory was further assessed by measuring the anamnestic response to a challenge dose of the monovalent vaccine, which was administered to subjects whose antibody concentrations fell below the pre-defined cut-offs (anti-HAV: <15mIU/mL; anti-HBs: <10mIU/mL).



209 subjects returned for follow-up at Year 15 of whom 162 were included in the long-term according-to-protocol immunogenicity cohort. All subjects remained seropositive for anti-HAV antibodies, while 81.1% and 81.8% still had anti-HBs antibodies ≥10mIU/mL in the 2- and 3-dose groups, respectively. Following hepatitis B vaccine challenge dose administration to 19 subjects, all except one in the 3-dose group, mounted a robust anamnestic response. The safety and reactogenicity profile of the hepatitis B challenge was consistent with previous experience.



Immunity to hepatitis A and B persists 15 years after adolescent vaccination with a combined hepatitis A and B vaccine. Highly effective anamnestic response indicates that a booster dose should not be required for 15 years after primary vaccination.



http://www.clinicaltrials.govNCT00875485.
Vaccination and Travel Medicine Centre, Hradec Kralove, Czech Republic.
Jiri
J
Beran
GSK Vaccines, Wavre, Belgium. Electronic address: olivier.x.van-der-meeren@gsk.com.
Olivier
O
Van Der Meeren
GSK Vaccines, Wavre, Belgium.
Maarten
M
Leyssen
GSK Pharmaceuticals, Mumbai, India.
Priya
P
D'silva
D000293:Adolescent; D000328:Adult; D005260:Female; D006506:Hepatitis A / Q000517:prevention & control*; D035922:Hepatitis A Antibodies / Q000097:blood; D022362:Hepatitis A Vaccines / Q000008:administration & dosage* / Q000627:therapeutic use; D006509:Hepatitis B / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000097:blood; D017325:Hepatitis B Vaccines / Q000008:administration & dosage* / Q000627:therapeutic use; D006801:Humans; D007156:Immunologic Memory; D008297:Male; D013997:Time Factors; D017778:Vaccines, Combined / Q000008:administration & dosage
D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines; D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines; D017778:Vaccines, Combined
Anamnestic response; Anti-HAV antibody; Anti-HBs antibody; Challenge dose; Combined hepatitis A and B vaccine; Long-term follow-up