Decreased severity of disease during the first global omicron variant covid-19 outbreak in a large hospital in tshwane, south africa oleh F. Abdullah, J. Myers, D. Basu, G. Tintinger, V. Ueckermann, M. Mathebula, R. Ramlall, S. Spoor, T. de Villiers, Z. Van der Walt, J. Cloete, P. Soma-Pillay, P. Rheeder, F. Paruk, A. Engelbrecht, V. Lalloo, M. Myburg, J. Kistan, W. van Hougenhouck-Tulleken, M.T. Boswell, G. Gray, R. Welch, L. Blumberg, W. Jassat