The World Health Organization said the new coronavirus and COVID-19, the respiratory disease it causes, were not known before the outbreak was first reported in Wuhan, central China, in December.

The first patient with COVID-19 in Italy was found on February 21 in a small town near Milan, in the northern region of Lombardy.

But the findings of Italian researchers, published by the scientific journal Tumori Journal of INT, show that 11.6% of 959 healthy volunteers enrolled in a lung cancer screening study between September 2019 and March 2020, developed antibodies to coronavirus long before since February.

Another specific test for antibodies to SARS-CoV-2 was performed by the University of Siena (Tuscany region) for the same research entitled “Unexpected detection of SARS-CoV-2 antibodies in the pre-pandemic period in Italy”.

He said four cases from the first week of October were also positive for antibodies that neutralize the virus, meaning they became infected in September, Giovanni Apolone, co-author of the study, told Reuters.

This is the main finding: asymptomatic people were not only positive after serological tests, but also had antibodies capable of killing the virus, Apolone said.

“It means that the new coronavirus can circulate among the population for a long time and with a low lethality rate, not because it disappears, but only to explode again,” he added.

Italian researchers told Reuters in March that they reported more than usual cases of severe pneumonia and the flu in Lombardy in the last quarter of 2019, a sign that the new coronavirus could have circulated earlier than previously thought.