Speaking to Swiss newspapers, David Nabarro said that infections could boom again if countries repeat what he said was a failure to prevent the second wave.
“They missed building up the necessary infrastructure during the summer months after they brought the first wave under the control,” he said in an interview with the Solothurner Zeitung.
“Now we have the second wave. If they don’t build the necessary infrastructure, we’ll have a third wave early next year.”
Dr Nabarro is a British expert who was appointed as one six WHO special envoys for the coronavirus pandemic. In 2017, he campaigned unsuccessfully to become the WHO director-general.
Europe enjoyed sinking infection rates in the summer, but they are now surging again.
Italy reported more than 34,000 new cases in one day on Saturday, the world’s third-worst tally after the US and India. Germany and France saw cases rise by another 33,000 combined. Switzerland and Austria have thousands of cases daily, while Turkey reported a record 5,532 new infections.
France is expected to start easing the restrictions it introduced on 30 October after the rate of new infections plummeted in the last few weeks. On Saturday, the number of new confirmed cases dropped for the fifth day in a row.
President Emmanuel Macron will give a speech on Tuesday 24 November and may announce a partial relaxation of the measures.
Nabarro singled out Switzerland’s move to allow skiing – with masks required in gondolas – as other Alpine nations like Austria and Italy have shuttered resorts. Nabarro said Switzerland could reach a “very high level of sicknesses and deaths”.
“Once the infection rates sink, and they will sink, then we can be as free as we want,” Nabarro was quoted as saying. “But right now? Should ski resorts open? Under what conditions?”
Nabarro lauded the response of East Asian countries like South Korea, where infections are now relatively low.
“People are fully engaged, they take on behaviours that make it difficult for the virus,” he said. “They keep their distance, wear masks, isolate when they’re sick, wash hands and surfaces. They protect the most endangered groups.”
Nabarro also said East Asian countries did not relax restrictions prematurely.
“You must wait until case numbers are low and stay low,” he said. “Europe’s reaction was incomplete.”
Additional reporting by Reuters