Second wave: What it is, and what it is notpublished at 11:25 BST 24 June 2020

Some countries are still dealing with large epidemics, but even those currently controlling the virus fear "the second wave".
The second phase of Spanish flu a century ago was deadlier than the first. So, is a second wave inevitable?
In order to say one wave has ended, the virus would have been brought under control and cases fallen substantially.
For a second wave to start you would need a sustained rise in infections.
Current outbreaks in New Zealand and the Chinese capital, Beijing, cannot be classed as a second wave, scientists argue. But the rapid surge in coronavirus cases in Iran in recent weeks has sparked talk of a second wave.
So what are our options? The BBC's James Gallagher takes a look.