On May 21, Ontario’s Chief Medical Officer of Health announced that individuals who received AstraZeneca/CoviShield Vaccine as their first dose will have a choice between 2 options for their second doses.

Option 1: Receive AstraZeneca/CoviShield vaccine for your second dose 12 weeks following your first dose (If you got your vaccine at our clinic March 24th, 12 weeks would be June 16th).

Option 2: : Receive an mRNA vaccine (Pfizer or Moderna) for your second dose 16 weeks following your first dose, if mixing vaccines is recommended (If you got your vaccine at our clinic March 24th, 16 weeks would be July 14th).

Please consider the following information when choosing between these 2 options:

  • Studies show that AstraZeneca works best when the 2 doses are spread out by 12 weeks and provide an estimated 80% protection against symptomatic disease.  When the 2 doses were given closer together (9-12 weeks), protection was estimated at 69%.
  • AstraZeneca/CoviShield has been linked with a type of blood clot called Vaccine-Induced Immune Thrombotic Thrombocytopenia (VITT).  The reported risk of VITT after the second dose of AstraZeneca/CoviShield vaccine is lower than after the first dose. Current estimates suggest a risk of 1 in 600,000 doses based on the data known to date.
  • Studies regarding the safety and effectiveness of mixing vaccines are currently underway and results are expected to be available in June 2021. Early information regarding the option of mixing vaccines currently appears favorable.

Here is more information from the Ministry of Health: COVID-19 Vaccine Information for Individuals that received a first dose of the AstraZeneca COVID-19 vaccine/COVISHIELD vaccine (gov.on.ca)

Please do not hesitate to reach out to us if you have questions or want to discuss further.

We are currently waiting to hear how all our AZ vaccine recipients will be able to receive a second dose and will communicate that process to you as soon as details are available.

Sincerely

The Peterborough 360 Degree NPLC Team