Another dose of AstraZeneca still an option in Quebec, but mRNA vaccine deemed 'preferable'
Province clarifies 2nd dose policy for those who received AstraZeneca as NACI issues its own guidelines
The National Advisory Committee on Immunization is going further than Quebec, recommending provinces should stop administering AstraZeneca-Oxford vaccine as a booster altogether.
Quebec appeared to take that stronger stance on Wednesday, but then walked it back this morning.
Health Minister Christian Dubé told reporters earlier today there was an "error of communication," after a notice on the province's website appeared to signal a significant change in the province's vaccination strategy.
The post Wednesday stated that people who received the AstraZeneca vaccine as a first dose should switch to an mRNA vaccine — either Pfizer-BioNTech or Moderna — for their second dose.
This raised questions, given that the province has been administering AstraZeneca as a second dose for nearly three weeks. On Thursday, Dubé apologized and said the wording was inaccurate.
"There was a statement yesterday that was wrong. People that have received AstraZeneca [as a first dose] should not necessarily take an mRNA [vaccine as a second dose," Dubé said at a news conference.
"There was a mistake."
The message on the government's website has since been modified. It now says that people who received AstraZeneca for their first dose "could receive" an mRNA vaccine and it "appears preferable" to do so, based on a review of research by Quebec's immunization committee (CIQ).
Dubé said people who received a dose of AstraZeneca still have the option of receiving a second dose of the same, or receiving Pfizer or Moderna.
What the advisory panels say
For its part, the CIQ recommends people aged 45 and up who received AstraZeneca for their first dose opt for Pfizer or Moderna for their second one, citing recent data that suggests doing so will provide stronger protection against COVID-19.
But the CIQ also states that choosing a second dose of AstraZeneca is still an option.
The National Advisory Committee on Immunization (NACI) went further Thursday. It recommended provinces stop administering the AstraZeneca as booster shots for people who already received first doses of the product.
"An mRNA vaccine is now preferred as the second dose for individuals who received a first dose of the AstraZeneca/COVISHIELD vaccine, based on emerging evidence of a potentially better immune response from this mixed vaccine schedule," NACI said in a statement released today.
Since early May, all provinces have halted the use of AstraZeneca for first doses. Many have continued using for booster shots.
Dr. Matthew Oughton, an infectious diseases specialist at Montreal's Jewish General Hospital, said early research suggests mixing doses is effective.
"When the first dose is AstraZeneca and the [booster] is Pfizer or Moderna, there have been a lot of hints that that will probably give you the best overall immune response," Oughton said.
Ultimately, an individual's decision in Quebec may come down to supply.
Quebec is running out of AstraZeneca doses and it's not clear when the next batch will arrive, while more Pfizer and Moderna is set to arrive in the coming weeks.