Dr. E. Kwok administers a COVID-19 vaccine to a recipient at a vaccination clinic run by Vancouver Coastal Health, in Richmond, B.C., Saturday, April 10, 2021. THE CANADIAN PRESS/Jonathan Hayward

Dr. E. Kwok administers a COVID-19 vaccine to a recipient at a vaccination clinic run by Vancouver Coastal Health, in Richmond, B.C., Saturday, April 10, 2021. THE CANADIAN PRESS/Jonathan Hayward

NACI says you can mix-and-match AstraZeneca, mRNA COVID vaccines

People who received AstraZeneca vaccine will have a choice for dose two

The National Advisory Committee on Immunization announced Tuesday (June 1) that Canadians who received AstraZeneca for their first dose can get an mRNA vaccine for their second dose.

“I think it’s good news that people now have that choice,” said chief medical health officer Dr. Theresa Tam.

The advice affects more than two million Canadians who received the Oxford-AstraZeneca vaccine before provinces stopped using it for first doses last month.

The vaccine is potentially linked to a rare but serious blood clotting syndrome.

In Canada, 41 confirmed or suspected cases of vaccine-induced thrombotic thrombocytopenia have been diagnosed and five people have died.

NACI’s published report says AstraZeneca recipients can be offered the same vaccine if they want it, or can be given either Pfizer or Moderna.

They say they are basing their advice on the risk of VITT, and emerging evidence that mixing and matching different types of vaccines is not only safe but may produce a better immune response.

The guidance is not binding but most provincial governments have indicated they were waiting for the information before setting their policies for second doses.

Manitoba didn’t wait for the report to be published, announcing Monday they would offer AstraZeneca recipients Pfizer or Moderna if they wanted.

Quebec currently recommends getting the same vaccine twice but says with informed consent people who got AstraZeneca first can get Pfizer or Moderna.

The province is expected to update this later in the week, along with shortening the wait to get second doses of mRNA vaccines.

NACI’s advice comes after interim results were published in May from two studies looking at mixing and matching vaccines.

A Spanish study concluded a second dose of Pfizer after a first dose of AstraZeneca produced more than twice the antibodies as a second dose of AstraZeneca.

A United Kingdom study reported there were more frequent reports of short-lived side-effects such as fever and fatigue in people whose second dose was a different vaccine. It is still waiting for results on how effective mixing and matching is but as second doses ramp up across Canada, health officials say they need to make decisions now.

Several European countries are giving Pfizer or Moderna as second doses to AstraZeneca recipients, including Denmark, Finland, France, Germany, Sweden, Norway and Spain.

More than two-thirds of Canadians over the age of 12 now have at least their first dose, but only about 10 per cent of them are fully vaccinated. With vaccine supplies limited in the first months of the immunization program, provinces delayed second doses up to four months to try and get more people one dose faster.

The plan has worked to that end, with Canada now one of the most vaccinated countries in the world when it comes to first doses. As of May 30, Canada is now in the top 10 countries for first doses in the world, and is likely to surpass the United Kingdom on first doses by the end of the week.

It’s not even in the top 50 for second doses.

Second doses are starting to be given faster now, with several provinces moving to fully vaccinate the highest risk populations, including seniors and those with compromised immune systems.

Until a week ago, fewer than one-tenth of new doses given out each were for second doses, but over the last week one-sixth of new doses were for second shots.

For some people, getting a different second dose is a supply issue, particularly for Moderna recipients, with that company unable to deliver expected doses on time so far.

For AstraZeneca however it is a question of safety. Provinces stopped using AstraZeneca for first doses in mid-May as the number of Canadians diagnosed with vaccine-induced thrombotic thrombocytopenia grew.

The rare blood clotting disorder believed to be caused by an unexpected immune response to the AstraZeneca vaccine, has occurred in about one in every 53,000 Canadians given the AstraZeneca vaccine as a first dose.

While health experts say the risks of the clots is extremely low and is outweighed by the risks of COVID-19, NACI said people should only get AstraZeneca if they are over the age of 30, and live in an area where they are more likely to be exposed to the virus that causes COVID-19.

Many provinces have been holding off giving second doses of AstraZeneca pending NACI’s advice on whether it should be given as second doses.

NACI has already said people can mix and match vaccines within the same vaccine family — so the mRNA vaccines from Pfizer and Moderna can be mixed and matched, or the viral vector vaccines from AstraZeneca and Johnson & Johnson.

That latter advice was theoretical since Canada hasn’t started using the J&J vaccine at this point. The 300,000 doses received in April remain in quarantine in freezers at Innomar Strategies pending a quality assurance check.

The drug substance in those doses was made at a facility in Maryland that has since been cited for numerous safety violations.

More to come.


Like us on Facebook and follow us on Twitter.

Coronavirusvaccines

Just Posted

An SUV sits where it crashed through the front window of the 2:18 Run store in Fairfield Plaza, after the driver appeared to lose control on Monday afternoon. (Photo by Phil Nicholls)
Driver crashes through front window of Victoria running store in Fairfield

Phil Nicholls of 2:18 Run said crash sounded like an earthquake at first

Processed sewage is still being deposited at the Hartland landfill rather than sent as biosolids to a Richmond cement plant. (Black Press Media file photo)
Biosolids at Hartland still being placed on landfill in Saanich

Richmond cement plant up and running, but CRD end product not suitable for purpose

The Greater Victoria Harbour Authority is calling on Transport Canada to rescind its ban to Feb. 28, 2022 on cruise ship stops in Canada, to allow planning to begin in advance of a reopening of the cruise industry next year.
Greater Victoria Harbour Authority seeks end to federal ban on cruise ship stops in Canada

Greater Victoria Harbour Authority CEO hopes cruises will resume by 2022

Seismic upgrading and expansion work at Victoria High School is about a year behind due to pandemic-related factors, the Greater Victoria School District announced. (Photo by Cole Descoteau)
Victoria High School seismic work, expansion a year behind schedule

Greater Victoria School District now targeting September 2023 for reopening of historic school

Elk Lake Drive area resident Michael Blayney protests a proposed multi-building development for his Royal Oak neighbourhood, outside Saanich municipal hall on Monday (June 14). (Photo by Megan Atkins-Baker/News Staff)
Demonstrators protest 11-storey development on Elk Lake Drive in Saanich

Saanich locals gather at municipal hall to protest development, public hearing goes Tuesday

Canadian Prime Minister Justin Trudeau participates in a plenary session at the G7 Summit in Carbis Bay, England on Friday June 11, 2021. THE CANADIAN PRESS/Adrian Wyld
Canada donating 13M surplus COVID-19 vaccine doses to poor countries

Trudeau says the government will pay for 87 million shots to be distributed to poor countries

Montreal Canadiens goaltender Carey Price (31) is scored on by Vegas Golden Knights defenseman Alec Martinez, not pictured, during the second period in Game 1 of an NHL hockey Stanley Cup semifinal playoff series Monday, June 14, 2021, in Las Vegas. (AP Photo/John Locher)
Habs fall 4-1 to Vegas Golden Knights in Game 1 of NHL semifinal series

Match was Montreal’s first game outside of Canada in 2021

Kelowna-Lake Country MLA Norm Letnick, assistant deputy speaker at the B.C. legislature, presides over committee discussions. The legislature is completing its delayed spring session this week, with most MLAs participating by video conference. (Hansard TV)
B.C.’s daily COVID-19 infections dip below 100 over weekend

Only 68 new cases recorded Monday, four additional deaths

A 30x40 ft boat/car shop in the Little River area near Wilkinson Road was fully involved by the time firefighters arrived on scene. Photo by Comox Fire Rescue
Comox firefighters battle ‘showy’ shop fire Saturday night

Smoke could be seen throughout the Comox Valley

Port Hardy council has agreed to cancel Canada Day celebrations in wake of the discovery of the remains of 215 children being found on the grounds of a former residential school. (North Island Gazette file photo)
Port Hardy cancels Canada Day celebrations in wake of Kamloops mass grave site revelation

Coun. Treena Smith made the motion for the chamber to not host Canada Day celebrations this year

Gabriola Island artist Sheila Norgate is promoting the Digital Innovation Group’s art impact survey. (File photo)
Vancouver Island artists get behind regional arts impact study

Artists urged to use their stature to help put arts and culture super-region on the map

Darren Campbell’s truck (pictured) was stolen when he stopped to check on a car in a ditch on Cowichan Bay Road on Monday morning. (Facebook photo)
Vancouver Island Good Samaritan’s truck stolen in nasty trick

‘Try to be a Good Samaritan and my $20,000 truck gets stolen right under my nose’

The Kamloops Indian Residential School is photographed using a drone in Kamloops, B.C., Monday, June, 14, 2021. The remains of 215 children were discovered buried near the former school earlier this month. THE CANADIAN PRESS/Jonathan Hayward
Communities grapple with what to do with former residential and day schools

Some tear them down as a tool to help healing, others repurpose them as tools for moving forward

Creative handmade signs abound at the June 13 Tofino rally for old growth trees. (Nora O’Malley photo)
VIDEO: Tofino stands in solidarity for Fairy Creek Blockades

Over 150 supporters attend rally hosted by Friends of Clayoquot Sound

Most Read