Estimating COVID-19 vaccine effectiveness against severe acute respiratory infections (‎SARI)‎ hospitalizations associated with laboratory-confirmed SARS-CoV-2

Overview

This guidance document proposes enhanced data collection within existing SARI surveillance systems. The document describes how existing hospital-based surveillance systems for SARI can be adapted to collect data to inform estimates of vaccine effectiveness against COVID-19 in persons of all ages. This document is intended to be used for developing site-specific protocols. It outlines in details methods for collecting and analysing data on vaccinated and unvaccinated patients based on the “test negative design” (TND), where cases are SARI patients who test positive for SARS-CoV-2, and controls are SARI patients who test negative for SARS-CoV-2.