Waning antibody levels after COVID-19 vaccination with mRNA Comirnaty and inactivated CoronaVac vaccines in blood donors, Hong Kong, April 2020 to October 2021. - Kwok SL; Cheng SM; Leung JN; Leung K; Lee CK; Peiris JM; Wu JT (Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin, 2022)