Abstract
AIMS: Severe acute respiratory syndrome coronavirus type 2 (SARS-COV-2) infection may increase the risk of developing dangerous symptoms among the elderly with underlying medical conditions. The aim of this study was to evaluate the safety and immunogenicity of the SARS-CoV-2 inactivated vaccine (Vero) in patients over 60 years of age with hypertension and/or diabetes. METHODS: An open-label, multi-center, prospective clinical trial was conducted at three medical sites in Fujian, China. Participants aged 60 years and above with hypertension, diabetes, and healthy controls were included in four groups: hypertension, diabetes, combined disease, and healthy controls. Volunteers received two doses of the inactivated SARS-COV-2 vaccine (BBIBP-CorV) on days 0 and 21. Adverse events were recorded for 21 days after each dose. Blood samples were taken before the first vaccination and 28 days after the second vaccination to detect the serum conversion rate and geometric mean titer (GMT) of neutralizing antibodies. RESULTS: A total of 480 participants (110 hypertension, 110 diabetes, 100 combined hypertension and diabetes, and 160 healthy controls) were recruited. The incidences of adverse events in the four groups were 10 (9.1%) in the hypertension group, 19 (17.3%) in the diabetes group, 11 (11.0%) in the combined disease group, and 11 (6.9%) in healthy controls, with no statistical significance (P > 0.05). At 28 days after the second vaccination, the positive conversion rates of serum neutralizing antibody in the four groups were 97.3%(107/110), 97.3% (107/110), 100.0% (99/99),and 98.7%(155/157), respectively, and the GMTs were 75.28 (95% CI 64.03-88.50), 69.4 (95% CI 59-81.63), 77.21 (95% CI 66.68-89.41), and 78.64 (95% CI 69.87-88.50), respectively. There was no significant difference in neutralizing antibody responses among the four groups (P > 0.05). Additionally, the GMT after immunization was higher in females than in males (OR = 2.59, 95% CI 1.31-5.12). CONCLUSIONS: The BBIBP-CorV vaccine is safe and elicits an adequate antibody response in patients over 60 years of age with hypertension and/or diabetes. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT05065879.