He also warned that a second wave could coincide with an outbreak of other infectious diseases.
“I’m very concerned about a double wave – in the fall, we could have a second wave of Covid and another one of seasonal flu or measles. Two years ago we had 500,000 children who didn’t have their first shot of the measles vaccine,” he said.
Many experts, including England’s chief medical officer, Professor Chris Whitty, have warned that a second wave of the pandemic could be even deadlier than the first, pointing to the 1918-20 Spanish flu pandemic as evidence.
When the Spanish flu first emerged in March 1918, it had the hallmarks of the typical seasonal illness – but it then came back in an even more virulent and deadly form in the autumn, eventually killing an estimated 50 million people.
Troop movements at the end of the First World War are thought to have accelerated the spread of the disease, which also had a third and fourth wave although these were not as devastating.
“We know from history that in pandemics the countries that have not been hit early on can be hit in a second wave,” said Dr Kluge. “What are we going to see in Africa and Eastern Europe? They’re behind the curve – some countries are saying: ‘We’re not like Italy’ and then, two weeks later, boom! They can unfortunately get hit by a second wave, so we have to be very very careful.”
In the last couple of weeks, many European countries have started unlocking their shuttered economies and allowing some resumption of normal life.
Earlier this month, the Spanish population was allowed to exercise outside for the first time in seven weeks, and restaurants in some areas of Germany have reopened.
And in France people will no longer need travel permits to explain why they have left home.
But in the absence of an effective treatment for the virus or a vaccine Dr Kluge said that any lockdown had to be accompanied by rigorous public health measures including comprehensive contact tracing and testing.
A pilot of an NHS contact tracing app was launched in the Isle of Wight last week, which the government said would be rolled out to the rest of the country by the end of the month if it proves successful. The number of tests being carried out has been growing slowly but is still not at the 100,000-a day-level promised by health secretary Matt Hancock.
Analysis by the Telegraph shows that around 80,000 tests a day are being carried out.