(CNN)Before December 20, there had not been any cases of Covid-19 among the nuns living at the Motherhouse campus of the Adrian Dominican Sisters in Adrian, Michigan.
Now, nine are dead of the disease after an outbreak with 48 of the campus' 217 residents testing positive. Thirteen active Covid-19 cases remain and 26 are recovering, Adrian Dominican Sisters said in a statement.
"We spent nine months keeping the coronavirus at bay. Right before Christmas, it slipped in," Sister Patricia Siemen told CNN affiliate WDIV. Siemen is the order's prioress, or leader.
"It's numbing," she said. "I have a much deeper appreciation for all of the other families who have gone through this. The hundreds of thousands of families. And until it personally touches you, I don't care how much we can have a sympathetic heart, it's different when you've been there and you've lost someone."
The nine sisters -- Dorothea Gramlich, 81, Helen Laier, 88, Jeannine Therese McGorray, 86, Charlotte Moser, 86, Esther Ortega, 86, Mary Lisa Rieman, 79, Ann Rena Shinkey, 87, Margaret Ann Swallow, 97, and Mary Irene Wischmeyer, 94 -- died between January 11 and 26. Most of the sisters were already at high risk due to existing health issues, WDIV reported.
The women all had served communities as teachers or nurses during their lifetime of religious service.
It's the latest of a number of such outbreaks at convents. Eight nuns living in the Notre Dame of Elm Grove in Wisconsin died from Covid-19 within a week late last year. In a convent outside Detroit, 13 nuns died within a month starting April 10.
The Our Lady of the Angels Convent in Greenfield, Wisconsin, lost six nuns in an outbreak last year.
Among the campus' 363 co-workers, 60 have tested positive, with 15 active cases, according to ADS.
Residents at the Motherhouse campus and more than 50 of the organization's frontline co-workers received the Moderna vaccine on January 15, and more co-workers continue to be vaccinated, ADS said.
"The care and safety of our Sisters and Co-workers have been and remain our primary concern. We continue to practice stringent protocols, including dedicated floors for COVID-19 patients, quarantines within our living communities, and weekly testing of all residents and Co-workers to mitigate further spread of the virus," their statement said.
The sisters are a religious order of more than 500 vowed women and 211 associates in 22 US states, the Dominican Republic, the Philippines, Mexico, and Norway. The order has been based at the Motherhouse campus since 1884.