Syndromic surveillance of vaccine-associated adverse events in US emergency departments

The Centers for Disease Control and Prevention explored use of emergency department (ED) visit data, during 2018-2020, from the National Syndromic Surveillance Program to monitor vaccine-associated adverse events (VAE) among all age groups. A combination of chief complaint terms and administrative diagnosis codes were used to detect VAE-related ED visits. Postvaccination fever was among the top 10 most frequently noted diagnoses. VAE annual trends demonstrated seasonality; visits trended upward starting in September of each year, coinciding with the administration of seasonal influenza vaccines. The 2020 VAE-related visit trend declined below the 2018 and 2019 baselines during March 22- September 5, 2020, before returning to the seasonal pattern. VAE-related visits declined in children aged 3-18 years in 2020 compared with 2018-2019, especially in the back-to-school months. These findings demonstrate that syndromic surveillance can complement traditional VAE reporting systems without an additional demand on data collection resources. Published by Elsevier Ltd.

Automated summary

The study used emergency department visit data to monitor vaccine-associated adverse events, finding that the number of related visits tended to increase during the seasonal influenza vaccine administration period.