But with signs the disease is peaking in the US and Europe, governments are starting to ease restrictions, weighing the need for economic recovery against cautions that lifting them too soon risks a second wave of infections.

The WHO warned on Saturday that there is still no evidence that people who test positive for the new coronavirus and recover are immunized and protected against reinfection.

The warning came as some governments study measures such as “immunity passports” or documents for those who have recovered as one way to get people back to work after weeks of economic shutdown.

“There is currently no evidence that people who have recovered from #COVID19 and have antibodies are protected from a second infection,” WHO said in a statement.