Surveillance for Adverse Events Following Immunization With COVID-19 Vaccines in Dalian, China (preprint)

ABSTRACT

Background: Coronavirus disease 2019 (COVID-19) vaccines have been administered in priority populations in China since December 15, 2020. This study aims to assess the safety of the COVID-19 vaccination programme in Dalian, China.Methods: Passive surveillance for adverse events following immunization (AEFIs) with COVID-19 vaccines was performed by the Dalian Center for Disease Control and Prevention (CDC). Data were collected through June 8, 2021, from the Chinese National Adverse Events Following Immunization System (CNAEFIS) and were verified by local and upper-level CDCs.Findings: A total of 7.12 million doses of vaccine were administered from November 27, 2020, through June 8, 2021, and 623 vaccinees reported adverse events, resulting in a rate of 87.5 events per one million doses. The age-specific rates of AEFIs ranged from 74.0 per one million doses among persons aged 45 to 59 years to 102.0 per one million doses among persons aged 18 to 44 years; the manufacturer-specific rates ranged from 81.1 to 125.2 per one million doses. Among the 623 AEFIs, 544 (87.3%; rate, 76.4 per one million doses) were confirmed as common minor vaccine reactions. Very rare cases of anaphylaxis after vaccination were reported (5 cases; 0.7 per one million doses). Seven cases of AEFIs were classified as serious; however, available information indicated that there was no causal relationship with COVID-19 vaccination.Interpretation: No major safety concerns were identified during the COVID-19 vaccination campaign. There was no evidence of an increased risk of serious adverse events (SAEs).Funding Information The study was supported by grants from the National Science Fund for Distinguished Young Scholars (No. 81525023), Key Emergency Project of Shanghai Science and Technology Committee (No. 20411950100).Declaration of Interests H.Y. has received research funding from Sanofi Pasteur GlaxoSmithKline, Yichang HEC Changjiang Pharmaceutical Company, and Shanghai Roche Pharmaceutical Company. None of those research funding is related to development of COVID-19 vaccines. All other authors report no competing interests.