COVID-19(127) SARS-CoV-2(123) coronavirus(65) virus(55) variant(53) Infection(45) acute respiratory syndrome(45) Viral(42) pandemic(41) Analysis(39) respiratory(38) acute respiratory syndrome coronavirus(36) Mutation(36) severe acute respiratory syndrome Coronavirus(36) ACE2(35) coronavirus disease(34) acute respiratory syndrome coronavirus 2(32) Genetic(32) identify(30) mechanism(30) reported(29) involved(29) Evolution(28) Frequency(26) Genes(26) Genome(26) Population(26) therapy(26) the SARS-CoV-2(25) Sequencing(24)