A vial of some of the first 500,000 of the two million AstraZeneca COVID-19 vaccine doses that Canada has secured through a deal with the Serum Institute of India in partnership with Verity Pharma at a facility in Milton, Ont., on Wednesday, March 3, 2021. THE CANADIAN PRESS/Carlos Osorio - POOL

A vial of some of the first 500,000 of the two million AstraZeneca COVID-19 vaccine doses that Canada has secured through a deal with the Serum Institute of India in partnership with Verity Pharma at a facility in Milton, Ont., on Wednesday, March 3, 2021. THE CANADIAN PRESS/Carlos Osorio - POOL

Federal panel recommends 4-month gap between COVID vaccine doses due to limited supply

The recommendation applies to all COVID-19 vaccines currently approved in Canada

The National Advisory Committee on Immunization (NACI) is supporting B.C.’s decision to delay the second doses of COVID-19 vaccines by up to four months.

“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 second dose of COVID-19 vaccine up to four months after the first,” the committee said in a decision published Wednesday (March 3).

The recommendation applies to all COVID-19 vaccines currently approved in Canada; Pfizer-BioNTech, Moderna and the newly approved AstroZeneca vaccine.

B.C. announced the decision to delay the second booster shot for four months on Monday, which health officials said could mean that all adults in the province could have their first dose by July.

READ MORE: Most B.C. adults could get their first COVID vaccine shot by July: health officials

Both provincial health officer Dr. Bonnie Henry and NACI said that its rationale was based on both the current available vaccine supply and data from other countries.

A study published by the University of Cambridge in the U.K., which has not yet been peer-reviewed, suggests that a single dose of the Pfizer-BioNTech vaccine can reduce the number of asymptomatic COVID-19 infections by 75 per cent.

In Israel, researchers studied the effects of a single dose of the same vaccine and published their findings in The Lancet medical journal, concluding that it was 85 per cent effective against symptomatic COVID-19 infections.

Also in The Lancet, a U.K. study found that the Oxford-AstraZeneca vaccine is 81 per cent effective when its second dose is given three months after the first, compared with 55 per cent efficacy after six weeks.

The national advisory committee noted that since the COVID-19 vaccines are still new, its unknown how long the protection of one or both doses lasts for.

“Experience with other multi-dose vaccines after a single dose suggests persistent protection could last for six months or longer in adolescents and adults,” NACI said in its statement. “Longer-term follow-up of clinical trial participants and those receiving vaccination in public programs will assist in determining the duration of protection following both one and two doses of vaccination.”

The national advisory committee added that it’s unknown how a delayed booster shot regime will affect the spread of variants of concern, including the U.K. and South African ones. However, NACI notes that there is “currently no evidence that an extended interval between doses will either increase or decrease the emergence of variants of concern.”

The committee noted that all three currently approved vaccines have shown “promising early result” against the U.K. variant B.1.1.7.

READ MORE: COVID-19 wage and rent subsidies, lockdown support to be extended until June

– with files from The Canadian Press


@katslepian

katya.slepian@bpdigital.ca

Like us on Facebook and follow us on Twitter.

Want to support local journalism during the pandemic? Make a donation here.

Coronavirusvaccines

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

The volume of visitors to White Rock’s Marine Drive over the weekend has led council to consider special measures this week. (Aaron Hinks photo)
White Rock council rejects resident-only parking for waterfront

Other health and safety measures to be considered in a special meeting Wednesday

South Surrey’s Paul Cottrell, who works with the DFO, tows a grey whale out of Semiahmoo Bay Sunday. (Contributed photo)
Dead whale floating near White Rock towed to shore for necropsy

Animal has been dead since at least April 15

Vehicles line up for the Greater Vancouver Drive-Thru Food Truck Festival at the Chilliwack Coliseum parking lot on March 27. The touring event comes to Cloverdale this weekend, April 24-25 (Photo: Jenna Hauck/Chilliwack Progress)
Here are the food trucks coming to Cloverdale for a drive-thru festival this weekend

Nine trucks will be parked Saturday, nine Sunday during event at fairgrounds

Pharmacist Barbara Violo arranges all the empty vials of the Oxford-AstraZeneca COVID-19 vaccines that she has provided to customers at the Junction Chemist which is a independent pharmacy during the COVID-19 pandemic in Toronto, on Monday, April 19, 2021. THE CANADIAN PRESS/Nathan Denette
Parts of Surrey, North Delta to get AstraZeneca vaccines for people ages 40+

A total of seven communities in Surrey and Delta will be targeted

The Braidwood Band performs for the seniors at Zion Park Manor in Surrey, as part of a music program planned by Rick’s Heart Foundation. (submitted photo)
VIDEO: Surrey charity brings distanced concerts to care homes, with prop pink firetruck

Familiar tunes performed for seniors during pandemic-era ‘Heart for Music’ program

In this image from NASA, NASA’s experimental Mars helicopter Ingenuity lands on the surface of Mars Monday, April 19, 2021. The little 4-pound helicopter rose from the dusty red surface into the thin Martian air Monday, achieving the first powered, controlled flight on another planet. (NASA via AP)
VIDEO: NASA’s Mars helicopter takes flight, 1st for another planet

The $85 million helicopter demo was considered high risk, yet high reward

(Twitter/IHIT)
1 man dead after shooting at Coquitlam park: IHIT

The gunman is still at large, according to the Integrated Homicide Investigation Team

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

Dr. Bonnie Henry gives her daily media briefing regarding Covid-19 for the province of British Columbia in Victoria, B.C, Monday, December 7, 2020. THE CANADIAN PRESS/Jonathan Hayward
Toddler marks youngest British Columbian to die related to COVID-19

Child one of eight people to die from virus this weekend

Families of two of three workers killed in a train derailment near Field, B.C., in 2019 have filed lawsuits accusing Canadian Pacific of gross negligence. The derailment sent 99 grain cars and two locomotives off the tracks. THE CANADIAN PRESS/Jeff McIntosh
Families of workers killed in Field train derailment allege negligence in lawsuit

Lawsuits allege the workers weren’t provided a safe work environment

(New Westminster Police)
4 youth arrested after 30-person brawl in New Westminster leaves 1 seriously injured

Police are looking for witnesses who saw the incident take place

Sunday’s storm rocked one of the ferries crossing Kootenay Lake. Photo: Dirk Jonker
VIDEO: Storm makes for wild ferry ride across Kootenay Lake

The video was captured by ferry employee Dirk Jonker

Chakalaka Bar & Grill remains open in defiance of orders from Island Health to close. (Cole Schisler photo)
B.C. health authority seeks injunction against restaurant defying COVID-19 orders

Chakalaka Bar and Grill plans to continue serving customers without public health compliance

Most Read