Coverage and effectiveness of COVID-19 vaccines among people aged 60 years and above in Changning District of Shanghai

Objective To assess the coverage and effectiveness of COVID-19 vaccines in the elderly.

Methods This study was conducted in Changning District of Shanghai， targeting people aged 60 years and above. Vaccination data between 21 December 2020 and 28 February 2022 was retrieved from the Shanghai Collective Immunization System. Information on confirmed cases of COVID-19 from March 2022 through May 2022 was collected from the National Notifiable Diseases Reporting System. Vaccine effectiveness was calculated using the screening method.

Results As of 28 February 2022， 69.89% of people aged ≥60 years had received ≥1-dose vaccine， 63.80% had received full primary vaccination and 31.91% had received a booster dose. Vaccination coverage declined over age， with the lowest coverage in the elderly aged ≥80 years. Moreover， COVID-19 vaccination provided the highest protection against severe/critical illness and death due to the Omicron variants in the elderly aged ≥60 years. Full primary vaccination showed 96.15%（95%CI：84.15‒99.06）of vaccine effectiveness and booster vaccination showed 100% of the effectiveness against severe/critical COVID-19 and death.

Conclusions Full primary and booster vaccination coverage in the elderly is low， especially in those aged 80 and above. Our study finds high protection against COVID-19 associated severe/critical illness and death from both full primary and booster vaccination of inactivated COVID-19 vaccines in the elderly aged ≥60 years.