Effect of vaccine booster, vaccine type, and hybrid immunity on humoral and cellular immunity against SARS-CoV-2 ancestral strain and Omicron variant sublineages BA.2 and BA.5 among older adults with comorbidities: a cross sectional studyCarol Ho-Yan Fong, Kelvin Kai‐Wang To, Ivan Fan‐Ngai Hung et al.|EBioMedicine|2023Cited by 27