Health Canada authorizes six doses per vial of the Pfizer-BioNTech COVID-19 vaccine, instead of five

Health Canada has authorized an increase in the number of doses in each vial of the Pfizer-BioNTech vaccine, from five doses to six.

Dr. Supriya Sharma, a senior medical advisor with Health Canada, said that it has been determined that six doses can be extracted from each vial "reliably" and "consistently," using low dead-volume syringes.

These syringes allow for a lower volume of liquid to stay in the "hub" of the syringe after the vaccine is administered.

Maj.-Gen. Dany Fortin, vice-president of logistics and operations at the Public Health Agency of Canada and head of the country’s vaccine distribution efforts, said Canada has acquired sufficient quantities of the appropriate syringe to get dix doses of the Pfizer-BioNTech vaccine from each vial, which will be distributed across Canada this week.

"What the company...has demonstrated through their studies is that if you're using those syringes relaibaly, using the good techniques in terms of drawing up the [doses] and administering them, that you should be able to get that sixth dose reliaby," Dr. Sharma said.

"We have heard anecdotally that in some cases people are able to extract a seventh dose as well, but certainly reliably, you should be able to get that sixth dose."

Pfizer is required to provide Health Canada with continued educational support and information regarding the low dead-volume syringes. The company must also work with provinces and territories to get any complaints or difficulties.

Pfizer is also required to advise Helath Canada within 24 hours of each site receiving their first shipment of supply with the new label change. The new label will also reflect that "very rare, severe allergic reactions," including anaphylaxis, have been reported under mass vaccination, outside of clinical trials.

Dr. Sharma indicated that most of these allergic reaction should occur within a few minutes or up to an hour after an individual receives the shot.

Maj.-Gen. Fortin reinforced that Pfizer will be "scaling up" production of their COVID-19 vaccine at the end of February. This change in Health Canada's authorization of the vaccine does not change the number of vials Canada will receive, but he expects Canada will receive and distribute approximately 400,000 doses next week and 475,000 doses in the last week of February.

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