Easter period may have bearing on magnitude and timing of third wave: Prof Madhi 2 March 2021 10:35 AM Share This: The publicâs behaviour over the Easter period will influence the severity and timing of the expected third wave, says Prof Shabir Madhi. Prof Madhi says the threat of a third wave of Covid-19 infections is inevitable, regardless of which lockdown level South Africa is placed under. However, the vaccinology expert says public behaviour will have a bearing on how soon and how hard the third wave hits. He believes that the next wave of Covid-19 infections could take place at the end of May and early June.