Leading B.C. doctor says 1 shot of COVID-19 vaccine is good enough — for now

Click to play video: 'New research points to two possible changes to speed up B.C. mass vaccination' New research points to two possible changes to speed up B.C. mass vaccination
WATCH: New research on the existing Pfizer coronavirus vaccine suggest one dose may be enough to create sufficient immunity. Other findings indicate the vaccine may be able to be stored and transported without the need for ultra-cold freezers. Aaron McArthur reports – Feb 19, 2021

Should Canadian public health officials be keeping second doses of COVID-19 vaccine on ice until all high-risk people get their first shot?

It’s a possibility Dr. Danuta Skowronski, epidemiology lead for influenza and emerging respiratory pathogens at the B.C. Centre for Disease Control, is raising.

Skowronski says data shows that there is little extra protection provided by a second COVID-19 shot. And it means the majority of hospitalizations from severe COVID should already be “vaccine preventable.”

Read more: Canadian researchers insist Pfizer’s 1st dose effective enough to delay 2nd

“We should not be waffling on this, it’s too critical right now,” she told Global News.

In a letter to the editor published in the New England Journal of Medicine co-authored with Dr. Gaston De Serres of the Institut National de Sante Publique du Quebec, Skowronski argues the Pfizer-BioNTech vaccine — initially said to be just 52.4 per cent effective with one dose — could also provide more than 90 per cent protection with a single shot.

Story continues below advertisement
Click to play video: 'New federal coronavirus modeling data warns of ‘third wave’ danger' New federal coronavirus modeling data warns of ‘third wave’ danger
New federal coronavirus modeling data warns of ‘third wave’ danger – Feb 19, 2021

According to Skowronski and De Serres, Pfizer’s own research started measuring how effective its vaccine was immediately after giving the shot, not after a two-week grace period she described as typical in vaccinology.

Read more: Canada prepares for single biggest Pfizer vaccine shipment to date

Using documents submitted to the U.S. Food and Drug administration, the doctors say they determined Pfizer’s vaccine is actually up to 92.6 per cent effective with a single dose.

[ Sign up for our Health IQ newsletter for the latest coronavirus updates ]

Evidence collected on the ground to date in British Columbia from long-term care residents and inoculated health-care workers indicates a single-shot efficacy of at least 80 per cent, Skowronski said.

Click to play video: 'New data on effectiveness of single COVID-19 vaccine dose' New data on effectiveness of single COVID-19 vaccine dose
New data on effectiveness of single COVID-19 vaccine dose – Feb 18, 2021

“What we’re showing, with that letter, is that the second dose gives very little added benefit over that first dose,” Skowronski said.

Story continues below advertisement

“We could be optimizing the use of the scarce vaccine supply by ensuring that all of our high risk individuals, target priority groups, get a first dose of vaccine before we double back and administer a second dose that is providing little added value to anyone at this stage.”

Read more: B.C. reports 508 new COVID-19 cases and 6 deaths, updates vaccine timeline

Skowronski stressed that she was not suggesting that second doses be dropped entirely, but that the priority should be getting first shots into the arms of people most at risk.

Pfizer is resistant to the idea of holding off on second doses.

In a reply to Skowronski and De Serres, the company insisted that “alternative dosing regimens … have not been evaluated.”

“The decision to implement alternative dosing regimens resides with health authorities; however, we at Pfizer believe that it is critical for health authorities to conduct surveillance on alternative dosing schedules to ensure that vaccines provide the maximum possible protection,” it said.

The federal government is seriously looking at the data.

Click to play video: 'Update on COVID-19 variants of concern in B.C.' Update on COVID-19 variants of concern in B.C.
Update on COVID-19 variants of concern in B.C – Feb 19, 2021

Federal Health Minister Patty Hajdu was asked Friday if a single-dose regimen, combined with new research showing the vaccine could possibly be kept at a warmer temperature, could be a “game changer.”

Story continues below advertisement

“It could be,” she said.

“The regulators are always renewing the new data as it arrives, from both the manufacturer and our own domestic data that continues to grow.”

Health officials in B.C. are actively discussing the possibilities the data opened up.

Read more: Administrator resigns at care home that was site of B.C.’s deadliest COVID-19 outbreak

“What we’re trying to do, what we’re all trying to do is maximize the protection from the available vaccine to the entire population,” deputy provincial health officer Dr. Reka Gustafson said.

“So I would say that the data are being looked at very, very carefully and evidence is accumulating to to support that as a potential approach for maximizing protection in the population.

The province has administered 192,942 doses of COVID-19 vaccine, of which 36,923 were second doses.

On Thursday, B.C. administered 12,250 doses of vaccine, its highest-ever single-day immunization. More than half of those shots were second doses.

Sponsored content