Real-world effectiveness of nirmatrelvir/ritonavir against COVID-19 hospitalisations and severe COVID-19 in community-dwelling elderly Singaporeans during Omicron BA.2, BA.4/5 and XBB transmission
Wee et al., Clinical Microbiology and Infection, doi:10.1016/j.cmi.2023.06.016
https://c19early.org/wee.html