ROME — Wearing a high-filtering mask over one’s nose and mouth at Mass “is a small sacrifice we can bring to the altar as an offering pleasing to God for the good of all his children,” said Father Roberto Colombo, a geneticist and member of the Pontifical Academy for Life.

As the omicron variant of COVID-19 swept across Italy and the government enacted stricter measures for the unvaccinated, the Italian bishops repeated that a vaccination certificate is not needed to attend Mass, but everyone in the congregation must wear a mask, maintain social distancing and receive Communion only in the hand.

Colombo, who teaches at the Catholic University of the Sacred Heart Medical School in Milan and is a member of the Italian government’s National Bioethics Committee, said wearing a mask at church is “a sign of pastoral charity” and a measure necessary for keeping churches open.

Writing Jan. 2 in Avvenire, the daily newspaper of the Italian bishops’ conference, Father Colombo said the rules for public liturgies worked out by the government and church authorities in May 2020 — after almost two months with no public celebrations of Mass — accomplished the goal of safeguarding people’s health without placing undue burdens on parishes or individuals.

The priest said the situation also was helped by the fact that, according to government statistics Jan. 3, more than 89 percent of Italians over the age of 12 had received at least one dose of a COVID-19 vaccine and close to 86 percent of the population was fully vaccinated. Many dioceses required priests and other pastoral workers to be fully vaccinated if they wanted to minister.

The high vaccination rate, Father Colombo said, is especially important because it means that “the elderly and people who are frailer also can participate in community celebrations safely” since the vaccines “reduce the probability of contracting COVID-19 in its most serious symptomatic forms.”

However, he said, because the omicron variant is highly contagious, people should start wearing high-filtering masks to Mass — the FFP2, similar to a U.S. N95, which the Italian government decreed in late December must be worn on all forms of public transportation, in theaters and for any concert or sporting event held indoors or in a stadium.

“In addition to a civic sense of responsibility for the common good, in our Christian communities there is also pastoral charity, which asks everyone — ministers and faithful — to be particularly attentive in wearing a mask correctly,” he said. “Of course, it can be uncomfortable, especially for the elderly, but it is a small sacrifice that we can bring to the altar as an offering pleasing to God for the good of all his children.”