Adult Inpatient SARS-CoV-2 Vaccine Effectiveness Surveillance is an observational, multicenter, prospective public health surveillance activity conducted by the Centers for Disease Control and Prevention (CDC) in collaboration with the Influenza and other Viruses in the acutelY ill (IVY) Network. Data collected on prior receipt of SARS-CoV-2COVID-19, and influenza, and RSV vaccination (once available) from enrolled patients.