They were tested after six cases among Vatican residents and employees were confirmed.
At least one of the six is still in the hospital right now.
Praying in a desolately empty St. Peter's Square, Pope Francis on Friday likened the coronavirus pandemic to a storm laying bare illusions that people can be self-sufficient and instead leaves "all of us fragile and disoriented" and needing each other's help and comfort.
Francis stood under a canopy erected on the steps of St. Peter's Basilica while leading a special prayer service as rain soaked the usually crowded cobblestone square. "Open our hearts to hope," he said in his opening prayer.
"Lord, may you bless the world, give health to our bodies and comfort our hearts," he prayed
At the end of the hour-long ceremony, he delivered a blessing that is traditionally reserved for the holy days of Christmas and Easter.
RELATED: Archdiocese of Chicago, Joliet Diocese won't hold public events for Palm Sunday, Holy Week, Easter amid COVID-19 outbreak
Wearing a simple white cassock, Francis climbed the sloping steps of the square by himself until he neared a canopied platform that had been erected to shelter him from the elements, taking the arm of an aide for the last steps.
Francis referred to the 17th-century colonnade that delineates St. Peter's Square while praying, "From this colonnade that embraces Rome and the whole world, may God's blessing come down upon you as a consoling embrace."
Then, moving to a temporary altar near the basilica's entrance, he prayed silently and listened to a series of invocations, including one that said, "Save us, O Lord, from illness, epidemics and fear of one's brother."
The Vatican has said that the faithful could receive what's known as a plenary indulgence - a lifting of temporal punishment - from sin with the special blessing, providing they meet other conditions, like going to confession or receiving Communion as soon as they can.
The prayer service was one of several scheduled over the next few weeks that will see the 83-year-old pontiff virtually solo in the square or celebrating Masses for Holy Week and Easter Sunday in the shelter of St. Peter's Basilica instead of outdoors in the company of tens of thousands of faithful.
Earlier on Friday, the Vatican announced that Francis will mark Holy Week ceremonies in the confines of Vatican City, including a Good Friday Way of the Cross service on the steps of the basilica, instead of at Rome's Colosseum as customary.
Because of the COVID-19 pandemic, Francis will celebrate Mass for Palm Sunday, Holy Thursday, and Easter vigil and Easter Sunday - April 12 - all at the basilica's central altar.
Before the pandemic, putting Italy and many other countries under stay-at-home orders that severely limiting people's movements in public, tens of thousands of faithful would have crowded the square on Palm Sunday and Easter for outdoor Mass celebrated by the pontiff.
Good Friday's candlelit procession at Rome's ancient Colosseum traditionally draws big crowds of tourists, pilgrims and Romans. But weeks ago, both tourists and pilgrims started fleeing Italy amid fears of virus contagion and as lock-downs by local and national authorities were gradually declared.
Italy's outbreak includes the world's highest total of dead for a single nation.
COVID-19 can cause mild or moderate symptoms, like fever and cough. But a small percentage of sufferers are hospitalized with pneumonia in intensive care.
The Holy See has confirmed four virus cases in the tiny independent city state in the middle of Rome.
It has declined to say if Francis, who a few weeks ago had a cold, has been tested for COVID-19, and if so, what the result was. Among the Vatican's confirmed cases is an Italian prelate who lives at a Vatican hotel where Francis resides.
Sunday ABC 7 will broadcast a Roman Catholic Mass celebrated by Cardinal Blase Cupich at Holy Name Cathedral.
You can watch on air or online at 9:30 a.m.
The Archdiocese of Chicago is also broadcasting Mass in English, Spanish and Polish on the archdiocese's YouTube channel Sunday's while churches are closed amid the coronavirus crisis.
RELATED: Archdiocese of Chicago to broadcast Mass from Holy Name Cathedral amid COVID-19 concerns
Chicago churches are also hoping to unite residents with the sound of church bells ringing. Cardinal Blase Cupich has asked Catholic parishes to ring their church bells five times a day.
ABC7 Chicago and the Associated Press contributed to this article.