Skip to main content Skip to Navigation Skip to Footer

Second Doses of the COVID-19 Vaccine

Any individual aged 16 years and older who received their first dose of Moderna or Pfizer at least 28 days ago can now make an appointment at a Pfizer clinic to receive Pfizer for their second dose. Updated recommendations from the National Advisory Committee on Immunization (NACI) guidelines confirm that interchanging mRNA vaccines is safe and effective. This recommendation is based on current scientific evidence and NACI’s expert opinion.

The Delta variant (B.1.617) present in our region is more transmissible compared to other doses and having two doses of a COVID vaccine offers increased protection against this variant.

Residents who received Moderna for their first dose and wish to receive Moderna for their second dose are encouraged to remain patient as the Ministry of Ontario has suggested additional allocations of Moderna may be received mid-June.

Additionally, individuals who received dose one of AstraZeneca will continue to follow the product monograph and receive dose two at a 12-week interval. They can choose either AstraZeneca or a mRNA vaccine (Moderna or Pfizer), as per NACI guidelines. The only exception to get a second dose before the 12 weeks is for individuals who are undergoing active treatment (i.e. chemotherapy or dialysis), and require a 4-12 week interval, at the discretion of their provider. With the AstraZeneca vaccine, a 12-week interval is recommended for optimal immunity.

Although walk-ins will continue to accepted for those looking for their first dose of a COVID-19 Vaccine, appointments are required for second dose clinics.  Walk ins for second doses will not be accepted for second doses. Individuals who are eligible can book an appointment online at or call the health unit at 1-800-461-1818. Please ensure you are booking your appointment in your community.