A cyclist crosses a near-empty Westminster Bridge with the Houses of Parliament in the background in central London on April 9, 2020. - British Prime Minister Boris Johnson on Thursday began a fourth day in intensive care "improving" in his battle with coronavirus, as his government prepared to extend a nationwide lockdown introduced last month. (Photo by ISABEL INFANTES / AFP)

A public health professor said Friday the British government responded too slowly to the COVID-19 outbreak, and the nation could see as many as 40,000 deaths before the pandemic is over.

Speaking remotely, University College London Global Health Professor Anthony Costello told a parliamentary committee the government needs to identify the “system errors” that slowed Britain’s response.

Britain imposed a lockdown on business and daily life March 23, about a week after other European countries, and Thursday announced a three-week extension on those measures.

Costello told the committee he expects a second wave of the virus to hit the country and urged the government to have a system in place to rapidly test people in the community and get the results back quickly.

Costello did say that an Oxford University researcher is 80 percent certain she could have a vaccine to treat the virus as early as September.

As of Thursday, Britain reported 13,729 people had died from the virus.