Information for individuals who received a first dose of the AstraZeneca COVID-19 vaccine

Advisory Alert

May 25, 2021

*Cette information est seulement disponible en anglais.

To: Health Care Providers

FOR IMMEDIATE ATTENTION

Primary care practitioners are asked to begin planning for second dose administration of the AstraZeneca COVID-19 vaccine

Effective May 21, 2021, the Government of Ontario announced that second dose administration of the AstraZeneca COVID-19 vaccine may proceed.

Individuals who received a first dose of AstraZeneca mid-March

The administration of second doses of AstraZeneca will begin with those who received their first dose of the vaccine between March 10 and March 19, 2021. During the week of May 24, these individuals can choose to receive their second dose of the AstraZeneca vaccine at an interval of 10 weeks, with informed consent. Receiving the second dose of AstraZeneca at a 10-week interval provides strong protection against COVID-19. Individuals who do not opt to receive the second dose of AstraZeneca at the 10-week interval will have an opportunity to schedule second dose appointments at the 12-week interval.

Individuals who received a first dose after mid-March

Individuals who received their first dose of the AstraZeneca vaccine and who do not receive their second dose during the week of May 24 will be able to schedule second dose appointments at the 12-week interval.

Primary care providers and pharmacies should ensure second dose appointments are scheduled in advance of the 12-week interval. Additional direction on how individuals who received their first dose of AstraZeneca can book a second dose appointment will be shared by the Ministry of Health soon. Further information will also be provided from the Ministry regarding the provision of AZ through the local primary care channel. Information will be shared as soon as it is available.

Informed consent for all second doses of AstraZeneca will ensure individuals understand the benefits and risks to receiving the vaccine. This process should be supported by discussion with a health care provider. Primary care providers and pharmacies are asked to review the options with their patients who received a first dose of the AstraZeneca COVID-19 vaccine noting that it is very important for people to receive two doses. Completing the vaccine series with the second dose will offer the best protection possible against COVID-19 and the variants of concern.

Alternate second dose options

The province continues to review the evidence on the administration of two doses of different vaccines. At this time, the National Advisory Committee on Immunization (NACI) does not recommend that vaccines of different types (e.g., mRNA vaccine and viral vector vaccine) be used in the two-dose series, as the data on immune response following mixed vaccine schedules is still being gathered.

The province will provide further guidance with respect to administering two different vaccines for first and second dose in the coming weeks. Further evidence and details from NACI are expected in the month of June. Additional details about local vaccine provision through primary care channels will be provided following Ministry direction.

It is important to remind patients that when the time comes to receive a second dose, everyone who received a first dose of the AstraZeneca vaccine will receive either an AstraZeneca or mRNA vaccine for their second dose to complete their vaccine series.

Sincerely,

Original Signed By

Dr. Penny Sutcliffe
Medical Officer of Health and Chief Executive Officer

NOTE: All Advisory Alerts are found on our website.

This item was last modified on May 25, 2021