Wee LE, Pang D, Chiew C, Tan J, et al. Long-term real-world protection afforded by third mRNA doses against symptomatic
SARS-COV-2 infections, COVID-19-related emergency attendances and
hospitalizations amongst older Singaporeans during an Omicron XBB wave. Clin Infect Dis 2023 Jun 6:ciad345. doi: 10.1093.
PMID: 37280047