Amphoe Phra Nakhon Si Ayutthaya

Researchers are evaluating the effectiveness of the tetravalent dengue vaccine (TDV) in reducing hospital stays due to dengue virus infections among children and adolescents in Southeast Asian countries with high dengue transmission, specifically Thailand, Indonesia, and Malaysia. This study focuses on participants aged 6 to 12 years who are part of a community-based cohort and may or may not receive TDV as part of a pilot public vaccination program. The research aims to provide further information on TDV's effectiveness, especially against the less common dengue virus types DENV-3 and DENV-4. This is a non-interventional study where participants are observed over a period of three years. Some cohort members may receive the TDV vaccine as part of a public vaccination program, while others may not be vaccinated. Researchers will compare hospitalization rates due to dengue between vaccinated and unvaccinated participants, without administering any study-specific treatments or interventions. Participants will be followed individually for three years, with their health monitored to identify any hospital stays caused by dengue infections. Blood samples may be collected at baseline and during illness episodes to confirm dengue infection using laboratory tests like RT-PCR. The primary outcome measured is hospitalization due to virologically confirmed dengue of any serotype. The study also includes matched case-control analyses within the cohort to better understand vaccine effectiveness and safety.