Newfoundland and Labrador has zero active cases, and as many provinces are looking to drop mask mandates, one doctor believes it may be best to keep masks around for now.

Dr. Lisa Barrett, an assistant professor in the Department of Medicine at Dalhousie University—who specializes in Infectious Disease and Immunology— says any place that removes mask mandates and doesn’t have high rates of fully vaccinated people will have more cases.

Dr. Barrett says the challenge with removing mandatory mask policies is that you won’t realize they are needed in indoor spaces and large public gatherings again until it’s too late.

Wearing masks is inexpensive and not hard to do, says Dr. Barrett. She says people can spread the virus without symptoms, even those who are vaccinated. She says vaccines are amazing, but not perfect and until most people are fully vaccinated, she thinks keeping masks around is a wise choice.