New data shows Quebec with 21 measles cases as of Friday 2 p.m., including 15 in Montreal.

According to the CIUSSS de l’Est, health centres in the eastern part of the island have responded by reinstating mask mandates and launching a vaccination campaign in elementary schools.

Notre-Dame and Sainte-Justine Hospitals are also among those requiring patients to wear masks to stop the spread.

“I feel like it’s necessary, especially to protect those who are more vulnerable,” said Montrealer Selena Ringwald. “Masking really doesn’t bother me, even as someone who has breathing issues after having COVID.”