This project will build on an existing CDC funded cooperative agreement in the Dominican Republic with the Brigham and Women's Hospital (2018-2023) that includes (i) prospective COVID-19 and AFI surveillance at two health facilities and (ii) a nationally representative cross-sectional community-based serological survey of approximately 7,000 healthy adults and children targeting SARS-CoV-2 and other AFI pathogens to be conducted between April and June 2021. This linked study will establish a nested cohort of 2,000 participants enrolled in the national serological survey and prospectively monitor them for COVID-19 symptoms, conduct serial serological testing, implement molecular surveillance for SARS-CoV-2 and sequencing for variants of concern, implement and evaluate WASH mitigation measures, and monitor uptake and perceptions of COVID-19 vaccines.

Inclusion Criteria:

• Previously enrolled in a linked national community-based seroepidemiological study in the Dominican Republic
• Agreed and consented to be recontacted to participate in additional research studies at the time of enrollment in #1
• ≥2 years of age
• Agree to participate

Exclusion Criteria:

• Ward of the State

De-identified data for epidemiological analyses and modelling (including demographic data, clinical data, and survey questionnaire survey) will be shared with the following collaborators: Adam Kucharski (LSHTM), Colleen Lau (University of Queensland), Marietta Vasquez (Yale University), Matt Lozier (US CDC), Pardis Sabeti (Broad Institute), and staff at the Health Ministry Division of Epidemiology. Non-identifiable data shared with listed collaborators will be performed with secure file transfer.