title: Long-term humoral and cellular immune response to hepatitis B vaccine in high-risk children 18-20 years after neonatal immunization.
abstract: Eighty-seven high-risk individuals in Thailand who had received a complete course of recombinant HBV vaccine 18-20 y ago were investigated with regard to their immunological memory. To evaluate humoral immunity, anti-HBs antibody titers were measured. Cellular immunity was determined by ELISPOT to detect HBV-specific IFN-gamma-producing cells. Overall 83.9% of participants developed circulating anti-HBs (titer > or = 1 mIU/mL) and 58.6% were seroprotected (titer > or = 10 mIU/mL). As for cellular immunity, 50.6% were positive on ELISPOT. Moreover, there was no correlation between the level of anti-HBs and positive ELISPOT results. However, the majority of participants (81.8%) who were positive for IFN-gamma-producing cells were seropositive, but only 50% of seropositive participants were ELISPOT-positive. Thus, 18-20 y after immunization, it appears that a second booster dose should be considered, especially in high-risk groups.
authors.affiliation: Department of Microbiology, Faculty of Medicine, Srinakharinwirot University, Bangkok, Thailand.
authors.forename: Teeraporn
authors.initials: T
authors.lastname: Chinchai
authors.forename: Chintana
authors.initials: C
authors.lastname: Chirathaworn
authors.forename: Kesmanee
authors.initials: K
authors.lastname: Praianantathavorn
authors.forename: Apiradee
authors.initials: A
authors.lastname: Theamboonlers
authors.forename: Yanee
authors.initials: Y
authors.lastname: Hutagalung
authors.forename: P Hans L
authors.initials: PH
authors.lastname: Bock
authors.forename: Pattarawat
authors.initials: P
authors.lastname: Thantiworasit
authors.forename: Yong
authors.initials: Y
authors.lastname: Poovorawan