- Correspondence to Professor Marietjie Venter, Medical Virology, University of Pretoria, Pretoria 0031, South Africa;
- Received April 22, 2020
- Accepted April 27, 2020
- First published May 13, 2020.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.