Dear Editor,
COVID-19 vaccination campaigns are being conducted in countries worldwide,and 47.4% of the world population has received at least one dose of a COVID-19 vaccine.1Although vaccination has shaped COVlD-19 epidemic curves,waning antibody levels and relatively short-duration protection provided by current COVID-19 vaccines have been observed,especially against SARS-CoV-2 variants of concern (VOCs) and among older individuals.