Journal Article

Phase 3 immunogenicity and safety study of a tick-borne encephalitis vaccine in healthy Japanese participants 1 year of age and older

de Solom, Richard, Yoshii, Chihiro, Watanabe, Tohru, Erber, Wilhelm, Aizawa, Masakazu, Yonekawa, Motoharu, Yamaji, Masako, Lockhart, Stephen P., Jug, Bogdan, Ito, Shuhei, Koelch, Doris, Kogawara, Osamu

2024

Overview

•TBE vaccine was evaluated in healthy Japanese participants 1 year of age and older.•TBE vaccine (3 doses) elicited robust immune responses in Japanese participants.•TBE vaccine was safe and well-tolerated in Japanese participants.•Safety and immunogenicity were consistent among Japanese and non-Japanese alike. Tick-borne encephalitis (TBE) virus infects the central nervous system and may lead to severe neurological complications or death. This study assessed immunogenicity, safety, and tolerability of TBE vaccine in Japanese participants 1 year of age and older. This phase 3, multicenter, single-arm, open-label study was conducted in Japanese adult (≥ 16 years) and pediatric (1−< 16 years) populations. Participants received a single 0.5-mL (adult) or 0.25-mL (pediatric) dose of TBE vaccine at each of 3 visits. The primary endpoint was the proportion of participants who were seropositive (neutralization test [NT] titer ≥ 1:10) 4 weeks after Dose 3. Secondary and exploratory endpoints included NT seropositivity rates 4 weeks after Dose 2, immunoglobulin G (IgG) seropositivity 4 weeks after Doses 2 and 3, NT geometric mean titers (GMTs), IgG geometric mean concentrations (GMCs), and geometric mean fold rises. Primary safety endpoints were frequencies of local reactions, systemic events, adverse events (AEs), and serious AEs. Among 100 adult and 65 pediatric participants, 99.0 % and 100.0 % completed the study, respectively. NT seropositivity was achieved in 98.0 % adult and 100.0 % pediatric participants after Dose 3; seropositivity after Dose 2 was 93.0 % and 92.3 %, respectively. In both age groups, IgG seropositivity was ≥ 90.0 % and ≥ 96.0 % after Doses 2 and 3, respectively; GMTs and GMCs were highest 4 weeks after Dose 3. Reactogenicity events were generally mild to moderate in severity and short-lived. AEs were reported by 15.0 % (adult) and 43.1 % (pediatric) of participants. No life-threatening AEs, AEs leading to discontinuation, immediate AEs, related AEs, or deaths were reported. No serious AEs were considered related to TBE vaccine. TBE vaccine elicited robust immune responses in Japanese participants 1 year of age and older. The 3-dose regimen was safe and well tolerated, and findings were consistent with the known safety profile of this TBE vaccine. ClinicalTrials.gov: NCT04648241.

• Publisher: Elsevier Ltd,Elsevier Limited
• Subject: Adolescent / Adult / Adults / Age / Age groups / Aged / Aged, 80 and over / Allergy and Immunology / Antibodies, Neutralizing - blood / Antibodies, Viral - blood / Arachnids / Central nervous system / Child / Child, Preschool / death / Dengue fever / Disease prevention / East Asian People / Encephalitis / Encephalitis Viruses, Tick-Borne - immunology / Encephalitis, Tick-Borne - immunology / Encephalitis, Tick-Borne - prevention & control / FDA approval / Female / Healthy Volunteers / Humans / IgG antibody / Immune response / Immunization / Immunogenicity / Immunogenicity, Vaccine / Immunoglobulin G / Immunoglobulin G - blood / Infant / Infections / Infectious diseases / International organizations / Japan / Male / Middle Aged / Neurological complications / Neutralization / Neutralization Tests / Patients / Pediatrics / Safety / seroprevalence / Tick-borne encephalitis / Tropical diseases / Vaccine / Vaccines / Viral Vaccines - administration & dosage / Viral Vaccines - adverse effects / Viral Vaccines - immunology / viruses / Young Adult