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

Soccer games returned to Max Turyk in Fernie this May and June, after a year-long break due to COVID. (Contributed by Yori Jamin)
Fernie kids get stuck into soccer

Youth soccer games returned to Max Turyk for May and June after a year-long break

A small scale example of how big the maximus dinosaur is compared to Sparwood's Titan truck. (Image courtesy of District of Sparwood)
Sparwood goes digging for fossils (maybe)

The district is exploring options that could see it acquire a giant dinosaur skeleton

Pride and Transgender flags wave on the lawn of Fernie's City Hall. (Soranne Floarea/ The Free Press)
Fernie Pride launches inclusivity survey

The survey will help identify gaps in supports for the LGBTQ2+ community in the Elk Valley

The freshly re-painted rainbow crossings in Fernie in 2021. (Scott Tibballs / The Free Press)
Rainbow crossings come to Fernie

Volunteers painted the crossings at 3rd Ave and 5th Street in Fernie in pride colours

Coal Creek and forested land near Fernie, B.C. (Scott Tibballs / The Free Press)
Elk Valley Regional Land Trust inks deal with Community Foundation of Kootenay Rockies

Donations to the trusts project to secure forested land in the Elk Valley can now be made through the CFKR

People watch a car burn during a riot following game 7 of the NHL Stanley Cup final in downtown Vancouver, B.C., in this June 15, 2011 photo. THE CANADIAN PRESS/Geoff Howe
10 years ago: Where were you during the 2011 Vancouver Stanley Cup Riots?

Smashed-in storefronts, looting, garbage can fires and overturned cars some of the damage remembered today

(Black Press Media file)
Dirty money: Canadian currency the most germ-filled in the world, survey suggests

Canadian plastic currency was found to contain 209 bacterial cultures

Cannabis bought in British Columbia (Ashley Wadhwani/Black Press Media)
Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

(pixabay file shot)
B.C. ombudsperson labels youth confinement in jail ‘unsafe,’ calls for changes

Review states a maximum of 22 hours for youth, aged 12 from to 17, to be placed in solitary

Grace (left), a caribou that was born in a maternal pen north of Revelstoke, is alive and well said the province. It appears she even has a calf. Maternity pens aim to increase caribou calf survival by protecting them from predation until they are older and less vulnerable. (Contributed)
For the first time in years, caribou numbers increasing near Revelstoke

North herd growing but south herd still concerning

Eleonore Alamillo-Laberge, 6, reads a book in Ottawa on Monday, June 12, 2017. THE CANADIAN PRESS/Sean Kilpatrick
Parents will need to fight ‘COVID learning slump’ over summer: B.C. literacy experts

Parents who play an active role in educating their children this summer can reverse the slump by nearly 80%, says Janet Mort

Kelowna General Hospital. (File photo)
COVID-19 outbreak at Kelowna General Hospital declared over

Three people tested positive for the virus — two patients and one staff — one of whom died

The border crossing on Highway 11 in Abbotsford heading south (file)
Western premiers call for clarity, timelines on international travel, reopening rules

Trudeau has called Thursday meeting, premiers say they expect to leave that meeting with a plan

Most Read