COVID-19(74) SARS-CoV-2(64) Patient(43) Infection(31) antibody(28) variant(26) vaccination(25) Vaccine(22) Mortality(22) Hospitalization(20) positive(19) COVID-19 patient(17) pandemic(16) respiratory(15) SARS-COV-2 infection(15) Abstract(14) COVID‐19(14) outcome(14) omicron(14) Critical(13) COVID‐19(13) coronavirus disease(13) Spike protein(13) SARS‐CoV‐2(13) virus(13) Older(13) patients(13) with COVID-19(13) Symptom(13) risk(12)