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Single-dose, live-attenuated Japanese encephalitis vaccine in children aged 12-18 months: randomized, controlled

Emmanuel Feroldi1, Chitsanu Pancharoen, Pope Kosalaraksa

  • 1Sanofi Pasteur Clinical Development Department, Marcy l'Etoile, France. Emmanuel.feroldi@sanofipasteur.com

Human Vaccines & Immunotherapeutics
|July 11, 2012
PubMed

Insights

This study confirmed that a new Japanese encephalitis chimeric virus vaccine (JE-CV) is consistent across manufacturing lots and effectively protects children. The vaccine demonstrated high seroconversion rates and a favorable safety profile in young children.

Area of Science:

  • Immunology
  • Vaccinology
  • Virology

Background:

  • Japanese encephalitis virus (JEV) poses a significant public health threat in Asia.
  • Live attenuated vaccines are crucial for controlling JEV transmission.
  • Ensuring manufacturing consistency is vital for vaccine efficacy and safety.

Purpose of the Study:

  • To assess the lot-to-lot consistency of a live attenuated Japanese encephalitis chimeric virus vaccine (JE-CV) manufactured at an industrial scale.
  • To compare the immunogenicity and safety of JE-CV produced from different manufacturing lots and a development lot.
  • To evaluate the protective immune response elicited by a single dose of JE-CV in Japanese encephalitis-vaccination naïve children.

Main Methods:

  • A clinical trial involving 1200 Japanese encephalitis-vaccination naïve children aged 12-18 months in Thailand and the Philippines.
  • Participants received JE-CV from three industrial scale lots or a development lot, or a hepatitis A control vaccine.
  • Antibody levels were measured using the 50% plaque reduction neutralization test (PRNT50) at screening and Day 28 post-vaccination.

Main Results:

  • Lot-to-lot consistency in seroconversion rates and geometric mean titers (GMT) was demonstrated between industrial scale lots and the development lot.
  • A high seroconversion rate of 95.0% (95% CI: 93.3-96.3) was observed 28 days after JE-CV vaccination.
  • The JE-CV vaccine exhibited a favorable safety profile, comparable to the hepatitis A control vaccine, with no serious adverse events related to vaccination.

Conclusions:

  • The study successfully demonstrated the manufacturing consistency of the JE-CV vaccine across multiple industrial scale lots and a development lot.
  • A single dose of JE-CV is well-tolerated and induces a robust protective immune response in JE-naïve children.
  • These findings support the reliable production and efficacy of JE-CV for Japanese encephalitis prevention.

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