Ten cases of COVID-19 have been confirmed at Atlantic Institution in Renous.
Three inmates and seven staff members at the maximum-security facility have tested positive, according to Correctional Service Canada.
CSC said measures are in place to minimize the spread of the virus within the institution.
Testing is being offered to inmates and staff, and employees must do a rapid test and provide a negative result before entering the site.
All staff and inmates are equipped with masks, and cleaning and disinfecting have been increased throughout the site.
Nearly 76 per cent of inmates at Atlantic Institution are fully vaccinated.