Exploring Temporal and Spatial Characteristics of Serious Adverse Event Reports Following COVID-19 Bivalent Vaccines

To mitigate the spread of variants such as Omicron in COVID-19 pandemic, the development and utilization of COVID-19 bivalent vaccines have become essential. However, an expected subset of individuals may experience serious adverse events (AE) after receiving the COVID-19 bivalent vaccine.

In this research, we conducted an in-depth analysis of data obtained from the Centers for Disease Control and Prevention (CDC) and the Vaccine Adverse Event Reporting System (VAERS) to evaluate the safety of COVID-19 bivalent vaccines administered between 9/15/2022 and 9/1/2023. The Standard Federal Regions were used for region partitions. To broaden our understanding of post-vaccination AE, we performed temporal analysis to investigate the trends of Top 10 reported AE in all serious adverse event reports. We also examined the similarity of AE across diverse regions within the United States.

Our findings indicated that a relatively stably decreasing trend was observed over time, with four peaks in December 2022, February 2023, Mar 2023 and April 2023. In terms of spatial analysis, the middle and northern regions exhibited higher rates of reported AEs associated with COVID-19 bivalent vaccine. An obvious similar pattern of AE is observed across regions (III, IV, V, VI, VII).

Overall, our research underscores the ongoing need for vigilant post-licensure vaccine monitoring, emphasizing the continuous surveillance and analysis essential for upholding the safety and effectiveness of COVID-19 bivalent vaccines.