Transmission(6) Recombination(6) reported(6) CoVs(6) human coronavirus(6) coronavirus(6) Human(6) coronavirus(6) China(6) severe disease(4) COVID-19(4) syndrome(4) Host(4) MERS(4) caused(4) humans(4) CoV(4) Mutation rates(4) acute respiratory syndrome(4) dead(4) Coronaviruses(4) Result(4) Health(4) zoonosis(4) information(4) Middle East(4) viruses(4) measure(4) approach(4) Saudi Arabia(4)