Kulkanya Chokephaibulkit1, Chukiat Sirivichayakul2, Usa Thisyakorn3, Chitsanu Pancharoen4, Mark Boaz5, Alain Bouckenooghe6, Emmanuel Feroldi7. 1. Division of Infectious Diseases, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. Electronic address: kulkanya.cho@mahidol.ac.th. 2. Department of Tropical Pediatrics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. Electronic address: chukiat.sir@mahidol.ac.t. 3. Department of Pediatrics, Chulalongkorn Hospital, Bangkok, Thailand. Electronic address: uthisyakorn@gmail.com. 4. Department of Pediatrics, Chulalongkorn Hospital, Bangkok, Thailand. Electronic address: Chitsanu.P@chula.ac.th. 5. Global Clinical Immunology, Sanofi Pasteur, Swiftwater, PA, USA. Electronic address: markjboaz@gmail.com. 6. Medical Affairs & Clinical Sciences, Sanofi Pasteur, Singapore. Electronic address: Alain.Bouckenooghe@sanofipasteur.com. 7. Clinical Sciences, Sanofi Pasteur, Marcy l'Etoile, France. Electronic address: Emmanuel.Feroldi@sanofipasteur.com.
Abstract
BACKGROUND: A single dose of live attenuated Japanese encephalitis chimeric virus vaccine (JE-CV) was shown to be immunogenic and well tolerated when given either as a booster to formalin-inactivated Japanese encephalitis (JE)-vaccine (mouse brain-derived vaccine [MBDV])-primed 2-5-year-olds, or as a primary vaccination to JE-vaccine-naïve 12-24-month-old toddlers in Thailand. A 5-year follow-up assessment of immune response persistence over time was conducted. METHODS: Four additional visits (at 2, 3, 4, and 5years) for immunologic assessments were added to the original 12-month open-label crossover study, in which 100 healthy children aged 2-5years with a history of two-dose primary vaccination with MBDV (according to the Thai Expanded Program for Immunization schedule), and 200 healthy JE-vaccine-naïve 12-24-month-old toddlers, were randomized 1:1 to receive JE-CV, containing ⩾4 log10 plaque forming units, 1month before or after hepatitis A control vaccine. RESULTS: In MBDV-primed 2-5-year-olds (n=78), the immune response to the JE-CV vaccine persisted up to at least 5years after vaccination with a single dose of JE-CV, with all (n=78) children seroprotected at the year 5 visit (geometric mean titers [GMT]: 2521/dil). There was no decrease of seroprotection rate over time (100% at 6months post-vaccination and 96.8% (90.3-98.9) at 5yearspost-vaccination). In JE-vaccine-naïve toddlers, a protective immune response persisted up to at least 5years in 58.8% (50.9-66.4) after a single-dose administration of JE-CV (GMT 26.71/dil; sensitivity analysis). CONCLUSIONS: A single-dose of JE-CV as a booster following MBDV administration provided long-lasting immunity. In JE-vaccine-naïve toddlers, despite relatively high seroprotection rates persisting over time, a subsequent booster dose is recommended following a JE-CV primary vaccination for long-term protection. This study was registered on www.clinicaltrials.gov (NCT00621764).
RCT Entities:
BACKGROUND: A single dose of live attenuated Japanese encephalitis chimeric virus vaccine (JE-CV) was shown to be immunogenic and well tolerated when given either as a booster to formalin-inactivated Japanese encephalitis (JE)-vaccine (mouse brain-derived vaccine [MBDV])-primed 2-5-year-olds, or as a primary vaccination to JE-vaccine-naïve 12-24-month-old toddlers in Thailand. A 5-year follow-up assessment of immune response persistence over time was conducted. METHODS: Four additional visits (at 2, 3, 4, and 5years) for immunologic assessments were added to the original 12-month open-label crossover study, in which 100 healthy children aged 2-5years with a history of two-dose primary vaccination with MBDV (according to the Thai Expanded Program for Immunization schedule), and 200 healthy JE-vaccine-naïve 12-24-month-old toddlers, were randomized 1:1 to receive JE-CV, containing ⩾4 log10 plaque forming units, 1month before or after hepatitis A control vaccine. RESULTS: In MBDV-primed 2-5-year-olds (n=78), the immune response to the JE-CV vaccine persisted up to at least 5years after vaccination with a single dose of JE-CV, with all (n=78) children seroprotected at the year 5 visit (geometric mean titers [GMT]: 2521/dil). There was no decrease of seroprotection rate over time (100% at 6months post-vaccination and 96.8% (90.3-98.9) at 5yearspost-vaccination). In JE-vaccine-naïve toddlers, a protective immune response persisted up to at least 5years in 58.8% (50.9-66.4) after a single-dose administration of JE-CV (GMT 26.71/dil; sensitivity analysis). CONCLUSIONS: A single-dose of JE-CV as a booster following MBDV administration provided long-lasting immunity. In JE-vaccine-naïve toddlers, despite relatively high seroprotection rates persisting over time, a subsequent booster dose is recommended following a JE-CV primary vaccination for long-term protection. This study was registered on www.clinicaltrials.gov (NCT00621764).
Authors: Luis Furuya-Kanamori; Narayan Gyawali; Deborah J Mills; Leon E Hugo; Gregor J Devine; Colleen L Lau Journal: Trop Med Infect Dis Date: 2022-05-29