Hidalgo

Researchers are evaluating the consistency of immune responses to three different batches of an investigational chickenpox vaccine called VNS vaccine in healthy children aged 12 to 15 months who have not had chickenpox or received a chickenpox vaccine before. The study also compares the safety and immune response of the VNS vaccine to an approved chickenpox vaccine known as Varivax. This Phase 3a study is sponsored by GlaxoSmithKline and aims to better understand the immune protection provided by these vaccines. Participants are randomly assigned to receive one dose of either one of the three investigational VNS vaccine lots or one of two lots of the marketed Varivax vaccine. Along with the chickenpox vaccine, they also receive one dose each of measles, mumps, and rubella MMR vaccine, hepatitis A vaccine HAV, and a pneumococcal conjugate vaccine PCV which could be PCV 13, Vaxneuvance, or PCV 20 depending on availability and country recommendations. All vaccines are given on Day 1 of the study. During the study, researchers monitor the participants immune responses by measuring antibodies against varicella zoster virus VZV and other vaccine components at Day 43. They also track safety by recording any side effects or adverse events from Day 1 to Day 181. The study includes diary reports by parents and regular clinical evaluations to assess immune response and safety outcomes. Participation involves a single vaccination visit and follow-up assessments over approximately six months.