Sudbury health unit follows national plan to extend the time interval between COVID-19 vaccines

·3 min read

You may get your COVID-19 vaccine earlier that you first expected, but it will likely take longer between your first and second doses. The information was released this week by Public Health Sudbury and Districts.

This follows a recommendation from the National Advisory Committee on Immunization (NACI) which suggested that the normal intervals for the Pfizer BioNTech vaccine and the Moderna vaccine are not necessarily required.

As the vaccines were being rolled out at the end of 2020, Pfizer said its recommended dosage interval was 21 days while Moderna said its recommended dosage interval was 28 days.

Things have changed based on the latest NACI recommendations.

"While studies have not yet collected four months of data on vaccine effectiveness after the first dose, the first two months of real world effectiveness are showing sustained high levels of protection," said part of the NACI summary.

"Extending the interval between doses was shown to be a good strategy through modelling, even in scenarios considering a six month interval and in theoretical scenarios where waning protection was considered," the summary continued.

"NACI recommends that in the context of limited COVID-19 vaccine supply, jurisdictions should maximize the number of individuals benefiting from the first dose of vaccine by extending the interval for the second dose of vaccine up to four months," said the NACI document.

In local terms, PHSD said this means the time interval for COVID-19 vaccines is being extended to 16 weeks.

"This allows vaccine distribution throughout the Public Health Sudbury & Districts service area to ramp up, offering more people their first dose of the COVID-19 vaccine," said a news release from PHSD. The release said the decision was in the context of limited vaccine supply and followed the NACI time interval recommendation.

"For certain groups, such as residents of long-term care and retirement homes, Elder Care Lodges and those in assisted living communities for seniors, at this time, the original dosing interval will apply," the release stated.

Dr. Penny Sutcliffe, Public Health Sudbury’s medical officer of health, was quoted saying that the change will allow the health unit to provide first doses to more people.

“Although I understand that people who have received their first dose were looking forward to receiving their second dose, they will need to wait a bit longer. This new guidance will mean rescheduling appointments to 16 weeks from the first dose, but will allow us to protect our communities faster,” said Sutcliffe.

Public Health Sudbury said it will rebook all appointments for second doses that now need to be rescheduled. Individuals will be informed of their new appointment either through email or phone and do not need to take any actions themselves, said PHSD.

Public Health Sudbury & Districts will work directly with individuals and partner agencies to ensure everyone receives their second dose within the recommended time frame. Individuals who receive their first dose of vaccine on March 10, 2021, or later will receive a booking for their second dose within 16 weeks, said PHSD.

“The evidence tells us that increasing the time between the first and second dose of the Health Canada approved two-dose vaccines still offers high effectiveness against symptomatic disease, hospitalization, and death from COVID-19,” said Dr. Sutcliffe.

Additional vaccination clinics will be held throughout the Sudbury and Manitoulin districts. PHSD advises that details about which groups of people are now eligible and the pre-registration process are available online and will also be shared broadly in the coming days and weeks.

Also, PHSD has created a lottery system to determine when your vaccine appointment happens.

To ensure fairness, people who have pre-registered online or by phone will be randomly selected to match the available number of vaccine doses, said PHSD. As vaccine supply is limited, it may take time to be selected for a vaccine appointment. Individuals whose names are selected will be contacted with details on how to book their appointment.

Len Gillis is a Local Journalism Initiative reporter at, covering health care in Northern Ontario. The Local Journalism Initiative is funded by the federal government.

Len Gillis, Local Journalism Initiative Reporter,