PRAGUE (Reuters) – Czechs flocked to screening centres on Thursday in a project to test 27,000 people for coronavirus antibodies to gauge how far the infection has spread and help decide how rapidly to ease the country’s lockdown.

The turnout was so large that at some locations the makeshift centres put up by the army reached capacity 15 minutes after testing began, leading officials to turn away some volunteers and advise them to return in the next few days.

“We want to prepare a reservation system to make it even more convenient for people,” Health Minister Adam Vojtech told a news conference about the government plan.

At one Prague location, long lines snaked out from the testing tent, while at another site for screening the elderly local media CTK reported that police had to calm disputes about queue-jumping.

The study, wider than others made in European countries and the United States in recent weeks, involves all age groups in four regions of the country and includes districts ranging from lightly to relatively heavily impacted by the virus.

Unlike standard testing of people suspected of being infected, it is aimed at currently healthy people who have not been diagnosed with the coronavirus in the past.

The results, expected in early May, should give officials in the nation of 10.7 million a clearer view of how many asymptomatic cases there may have been as they debate how fast to ease restrictions.

A higher proportion of people with antibodies would suggest the virus may be more widespread and less deadly than thought, which could point to less need for lockdown measures. Czech officials have said, however, that they believe the rate of people who have contracted the virus would be low.

It also follows similar but much smaller surveys in a number of other countries. In one, Los Angeles County residents showed 4.1 percent of adults tested positive for antibodies, suggesting the infection rate could be 40 times higher than the number of confirmed cases.

The Czech Republic has experienced a less severe outbreak than in most west European countries after the nation quickly adopted strict measures such as shop and school closures, a ban on most foreign travel, and mandatory face mask use in public.

The Czech Republic has reported 7,136 cases and 210 deaths while carrying out 195,725 tests.

(Reporting by Michael Kahn and Jan Lopatka, Editing by William Maclean)