Epidemiological and molecular description of nosocomial outbreak of COVID-19 Alpha (B.1.1.7) variant in Saudi Arabia oleh Asim Alsaedi, Maher Alharbi, John Ossenkopp, Fayssal Farahat, Roxanne Taguas, Mousa Algarni, Ahmad Alghamdi, Liliane Okdah, Sadeem Alhayli, Abdulrahman Alswaji, Michel Doumith, Aiman Al-Saed, Mohammed Alzahrani, Majid Alshamrani, Majed F. Alghoribi