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AstraZeneca Vaccine

Common questions and answers to pausing the administration of the AstraZeneca vaccine

Why is the Ontario government pausing the use of AstraZeneca?

This decision was made out of an abundance of caution due to an observed increase in the rare blood clotting condition, known as vaccine-induced immune thrombotic thrombocytopenia (VITT). Over last few days, there have been increased reports of VITT (1.7 per 100,000, up from 0.9 per 100,000 doses administered).

The decision to pause is also based on the increased and reliable supply of the Pfizer and Moderna mRNA vaccines and the downward trend in cases.

Public Health Ontario, the Science Advisory Table and federal, provincial, and territorial partners, are reviewing the data to consider options for the use of the AstraZeneca vaccine moving forward.

I already received my first dose of AstraZeneca, what about my second dose?

Ontario is pausing the rollout and administration of first doses of the AstraZeneca vaccine at this time.

Data from the UK points to a much-reduced risk of vaccine-induced immune thrombotic thrombocytopenia (VITT) in second doses of AstraZeneca, and more guidance will be coming to those needing to receive their second dose of the AstraZeneca vaccine.

The National Advisory Committee on Immunization (NACI) is also looking into the interchangeability of COVID-19 vaccines.

Based on the much higher risks of COVID-19 infection recently observed in Ontario including hospitalization, serious illness and death, we maintain that those who received their first dose with the AstraZeneca vaccine did absolutely the right thing to prevent illness, and to protect their communities.

I already received the AstraZeneca vaccine, should I be worried?

Individuals who received the AstraZeneca COVID-19 vaccine were asked to monitor for the following symptoms for 20 days after receiving the vaccine: shortness of breath, chest pain, leg swelling, persistent abdominal pain, neurological symptoms including sudden onset of severe or persistent worsening headaches or blurred vision, skin bruising (other than at the site of vaccination) or petechiae.

If you received your vaccine within the past 20 days, please continue to monitor. If it has been more than 20 days, you are unlikely to experience any side effects related to AstraZeneca.

Based on the much higher risks of COVID-19 infection recently observed in Ontario including hospitalization, serious illness and death, we maintain that those who received their first dose with the AstraZeneca vaccine did absolutely the right thing to prevent illness, and to protect their communities.

Why did the government approve AstraZeneca if it isn’t safe?

Health Canada has completed a rigorous scientific review of the available medical evidence to assess the safety of the AstraZeneca COVID-19 Vaccine. As with all vaccines, there was continued monitoring for the safety and efficacy of the AstraZeneca COVID-19 vaccine after authorization.

This decision was made out of an abundance of caution due to an observed increase in the rare blood clotting condition, known as vaccine-induced immune thrombotic thrombocytopenia (VITT). Over last few days, there have been increased reports of VITT (1.7 per 100,000, up from 0.9 per 100,000 doses administered).

Public Health Ontario, the Science Advisory Table and federal, provincial, and territorial partners, are reviewing the data to consider options for the use of the AstraZeneca vaccine moving forward.