Abstract:Objective To analyze the adverse reactions of novel coronavirus vaccine (SARS-CoV-2 vaccine) and the impact on previous underlying diseases after different vaccination numbers in the elderly over 60 years old ,and to explore the safety and tolerance of SARS-CoV-2 vaccine. Methods By means of a questionnaire survey and telephone return visit, the basic information were collected among 2103 elderly people over 60 years old who were vaccinated with Sinovac-CoronaVac vaccine(Vero cell) in Jiangbei New District of Nanjing from July 2021 to July 2022. They were divided into control group (without basic diseases, n=1346) and chronic disease group (with basic diseases, n=757) according to whether there were basic diseases or not. At 30 minutes, 1-, 3-, 7- and 14-day after vaccination, the adverse reactions and the impacts on the underlying diseases were observed and compared between two groups. Results Out of 2103 persons surveyed, only 86(4.09%) subjects had one or more adverse reactions after vaccination. The most common local and systemic adverse reactions were pain at the injection site(2.48%) and fatigue(0.24%), followed by fever(0.14%) and headache(0.19%). All adverse reactions were mild(grade 1 or 2) and self-limiting. Multivariate logistic regression analysis showed that previous underlying diseases, smoking and vaccination numbers had no significant impacts on adverse reactions after vaccination(P>0.05). Conclusion The incidence of adverse reactions after SARS-CoV-2 vaccination is low, and the safety is high for the elderly over 60 years old with stable health and good drug control.