title: Persistence of immunity 18-19 years after vaccination against hepatitis B in 2 cohorts of vaccinees primed as infants or as adolescents in Italy.
abstract: This study was aimed at assessing the anti-HBs persistence and immune memory 18-19 y after vaccination against hepatitis B in healthy individuals primed as infants or adolescents. We enrolled 405 teenagers (Group A) vaccinated as infants, and 409 young adults (Group B) vaccinated as adolescents. All vaccinees were tested for anti-HBs and anti-HBc antibodies; those found anti-HBc positive were further tested for HBsAg and HBV DNA. Eight individuals belonging to Group B were positive for anti-HBc alone, and were excluded from analysis. Individuals with anti-HBs concentration ≥ 10 mIU/ml were considered protected while those with anti-HBs concentration <10 mIU/ml were offered a booster dose and re-tested 2 weeks later. Overall, 67.9% individuals showed anti-HBs concentrations ≥ 10 mIU/ml (48.9% in Group A vs 87.0% in Group B, p < 0.001). The antibody geometric mean concentration (GMC) was higher in Group B than in Group A (102.5 mIU/ml vs 6.9 mIU/ml; p < 0.001). When boosted, 94.2% of vaccinees with anti-HBs <10 mIU/ml belonging to Group A and 94.7% to Group B showed an anamnestic response. Post-booster GMCs were similar in both groups (477.9 mIU/ml for Group A vs 710.0 mIU/ml for Group B, p = n.s.). Strong immunological memory persists for at least 18-19 y after immunization of infants or adolescents with a primary course of vaccination. Thus, booster doses are not needed at this time, but additional follow up is required to assess the long-life longevity of protection.
authors.affiliation: a Dipartimento di Scienze Biomediche per la Salute , Università degli Studi di Milano , Milano , Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Romanò
authors.affiliation: a Dipartimento di Scienze Biomediche per la Salute , Università degli Studi di Milano , Milano , Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Galli
authors.affiliation: a Dipartimento di Scienze Biomediche per la Salute , Università degli Studi di Milano , Milano , Italy.
authors.forename: Catia
authors.initials: C
authors.lastname: Tagliacarne
authors.affiliation: b Centro Nazionale di Epidemiologia, Sorveglianza e Promozione della Salute , Istituto Superiore di Sanità , Roma , Italy.
authors.forename: Maria Elena
authors.initials: ME
authors.lastname: Tosti
authors.affiliation: c Servizio di Immunoematologia e Medicina Trasfusionale, Policlinico S Orsola Malpighi , Bologna , Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Velati
authors.affiliation: d Servizio di Immunoematologia e Medicina Trasfusionale, ASST della Valtellina e dell'Alto Lario, Presidio di Sondrio , Sondrio , Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Fomiatti
authors.affiliation: e Dipartimento di Scienze Biomediche ed Oncologia Umana , Università di Bari , Bari, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Chironna
authors.affiliation: f Dipartimento di Sanità Pubblica , Medicina Clinica e Molecolare, Università di Cagliari , Cagliari , Italy.
authors.forename: Rosa Cristina
authors.initials: RC
authors.lastname: Coppola
authors.affiliation: g Settore Igiene Pubblica, Servizio di Epidemiologia e Prevenzione, ASP Catania , Catania , Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Cuccia
authors.affiliation: h Servizio di Sanità Pubblica, Epidemiologia e Medicina Preventiva , ASP Agrigento, Distretto di Licata , Licata , Agrigento , Italy.
authors.forename: Rossana
authors.initials: R
authors.lastname: Mangione
authors.affiliation: i UO Pediatria e Consultorio Familiare , Pediatria di Comunità, AUSL della Romagna-Cesena , Cesena , Italy.
authors.forename: Fosca
authors.initials: F
authors.lastname: Marrone
authors.affiliation: j Dipartimento Prevenzione Collettiva Salute Umana , ASP Potenza , Potenza , Italy.
authors.forename: Francesco Saverio
authors.initials: FS
authors.lastname: Negrone
authors.affiliation: k Dipartimento di Prevenzione , Servizio Dipartimentale di Epidemiologia e Prevenzione, ASL Napoli 2 Nord , Napoli , Italy.
authors.forename: Antonino
authors.initials: A
authors.lastname: Parlato
authors.affiliation: l Dipartimento di Scienze della Sanità Pubblica e Pediatriche , Università di Torino , Torino , Italy.
authors.forename: Carla Maria
authors.initials: CM
authors.lastname: Zotti
authors.affiliation: b Centro Nazionale di Epidemiologia, Sorveglianza e Promozione della Salute , Istituto Superiore di Sanità , Roma , Italy.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Mele
authors.affiliation: a Dipartimento di Scienze Biomediche per la Salute , Università degli Studi di Milano , Milano , Italy.
authors.forename: Alessandro Remo
authors.initials: AR
authors.lastname: Zanetti
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000097:blood*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D007156:Immunologic Memory; D007223:Infant; D007558:Italy / Q000453:epidemiology; D008297:Male; D013997:Time Factors; D055815:Young Adult
chemical_list: D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines
keywords: HBV; hepatitis B; immune memory; long-term immunity; vaccination