ABSTRACT
People living with chronic disease, particularly seniors older than 60 years old, are lagging behind in the national COVID-19 vaccination campaign in China due to the uncertainty of vaccine safety and effectiveness. However, this special population made up of most severe symptom and death cases among SARS-CoV-2 infected patients and should be prioritized in vaccination program. Thus, safety and immunogenicity data of COVID-19 vaccines in people with underlying medical conditions are needed to address the vaccine hesitancy in this special population. Here, we report a retrospective cohort study evaluating the immunogenicity and safety of the inactivated COVID-19 vaccine, CoronaVac, in people with at least one of the six common diseases, focusing on seniors (N = 969). We found that CoronaVac is as safe in people with chronic diseases as that in healthy control, without serious adverse event reported in this study. By day 14-28 post vaccination, we observed no significant difference for the antibody responses between disease groups and healthy control, except for the coronary artery disease (p=0.03) and chronic respiratory disease group (p=0.04) showing moderate reduction. Such difference diminished by day 90 and 180, as neutralizing antibodies significantly reduced in all participants. Most people showed detectable SARS-CoV-2-specific T cell response at day 90 and day 180 without significant difference between disease groups and healthy control. Overall, our results highlight the comparable safety, immunogenicity and cellular immunity memory of CoronaVac in seniors and people living with chronic diseases, addressing vaccine hesitancy for this special population.