Turn of the coronatide

It may not be the beginning of the end, but in parts of the world that are detecting fewer cases of COVID-19, it is starting to look like the end of the beginning. Maritime metaphors are in heavy demand. Maybe it’s the thought of returning to the beach, as some have already done. The storms that have just battered southern Australia are a rough reminder that nature is unpredictable. These events can come without warning, and may return in waves. So just what is this COVID-19 second wave?