The Thomistic Institute's document also recommends that the Precious Blood ought not be distributed at Mass.
To date, dioceses that have developed Church reopening plans have called for suspension of distribution of the Precious Blood. The Catholic Church teaches that reception of either the host or the chalice is a complete act of Eucharistic reception.
The Thomistic Instutute's website does state, however, that the guidelines "will be updated as the situation changes and as the WHO/CDC guidance changes."
Deacon Tim Flanigan is a member of the Thomistic Institute's working group, an infectious disease specialist who has battled Ebola outbreaks, and a professor of medicine at Brown University. Flanigan also told CNA that Catholics can return to Mass and the sacraments safely if they observe CDC protocols.
"The question is: can I follow the CDC guidance just as carefully, in each setting, in order to decrease transmission of coronavirus? Can I maintain safe distancing? Can I maintain good hand hygiene? Can I ensure that I am not ill?" Flanigan told CNA last week.
If CDC guidelines are followed, "There is no reason to prohibit church services when you don't prohibit other gatherings," Flanigan said.
"The CDC gives us that guidance to decrease the rate of transmission. It's just as important that guidance be followed at a house of worship, as at a conference, as at any other gathering."
An ad-hoc committee of seven Catholic doctors and medical school professors released on May 12 a plan entitled "Road Map to Re-Opening our Catholic Churches Safely."
That group of doctors concluded that "choirs and singing should be avoided" due to the aerosol risk.
They also concluded that the safest recommendation is to receive Communion in the hand rather than on the tongue. The plan does not contain specific guidance on the use of the cup at Mass.
The doctors' plan calls for Mass to be held with social distancing, and for the use of masks and hand sanitizer. Those who are ill or believe they may have been exposed to the virus should stay home, it says.
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Churches have been the focus of concern during the epidemic because of the close proximity of church attendees, socialization before, during and after services, and singing. Some churches have older congregations and so are believed to be more vulnerable to extreme consequences from coronavirus infection.
A May 22 article from the CDC reported that among the 92 attendees at a rural Arkansas church, 38% developed a laboratory-confirmed case of infection after a pastor and his wife, who had the virus, attended several events there in early March.
Twenty-six additional cases- including one death- in the community also were linked to the church.
The CDC had also, earlier this month, released a report chronicling a COVID-19 "superspreader" event, whereby a single symptomatic person infected more than 50 people- two of whom died- at a choir practice in Washington state in March.
Deacon Robert Lanciotti, a microbiologist and the former chief of the Center for Disease Control and Prevention's diagnostic and reference laboratory in Fort Collins, Colorado, told CNA that in his opinion, the Washington state "superspreader" example does not entirely exclude the possibility of singing in church.
"The key issue here is that a symptomatic individual practiced for 2.5 hours in close contact with others with no facial coverings," Lanciotti pointed out.