2 South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
3 School of Public Health, The University of Hong Kong, Hong Kong, Hong Kong SAR, China.
4 Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom.
5 Department of Microbiology and Immunology, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States.
6 Institute for Medical Virology, University Hospital Frankfurt, Goethe University Frankfurt, Frankfurt, Germany.