Cluster-Randomized Trial of Air Filtration and Ventilation to Reduce Covid19 Spread in Homes

Inclusion Criteria: * Household members live in a shared space (apartment, home) with others (as opposed to renting single rooms in a shared space, for example) * At least 3 other people live in the household aside from index case Exclusion Criteria: * If index case test positive day was over 2 days prior * If half or more household members are thought to be infected already * If household has fewer than 3 contacts interested in participating in the study * If fewer than 3 contacts are expected to be present in the house for a majority of the following 7 days