OTTAWA -- The National Advisory Committee on Immunization (NACI) is dropping the age of eligibility it is recommending for those who can receive the AstraZeneca vaccine to anyone 30 years of age and older, but it remains up to the provinces and territories to determine whether based on their current supplies if it makes sense to expand access.

“At this time, and based on current evidence, NACI recommends that the AstraZeneca COVID-19 vaccine may be offered to individuals 30 years of age and older, without contraindications, if the individual does not wish to wait for an mRNA vaccine, and the benefits outweigh the risks,” said NACI vice-chair Dr. Shelley Deeks.

She said NACI factored in the timing of expected access to mRNA vaccines in its latest guidance, however, based on the current vaccine schedule, it’s becoming increasingly likely that people will be waiting for more shipments of the viral vector vaccines like AstraZeneca, whereas the mRNA vaccine from Pfizer-BioNTech will soon regularly be bringing in more than two million doses per week, with millions more Moderna mRNA doses promised before the end of June.

With just 2.3 million total doses of the AstraZeneca vaccine distributed across Canada, due to various global factors, there’s considerable uncertainty about when future shipments will arrive.

“Because most of our [vaccine] programs are based on age, there are some people that are not yet eligible for the main part of the program, and the AstraZeneca is an important vaccine for us to have available,” said British Columbia’s top public health officer Dr. Bonnie Henry during Friday’s press conference, explaining why the updated guidance may allow some higher risk Canadians to gain access to a vaccine shot earlier.

NACI has yet to issue any guidance around the use of the single-shot Johnson & Johnson viral vector vaccine, which Health Canada has also approved for use in anyone 18 years of age and older. The first shipment of 300,000 doses is expected to be delivered the week of April 27, and be in provinces and ready to administer in early May.

NACI’s updated advice about the usage of the two-dose viral vector vaccine is an update to NACI’s guidance in March recommending that the vaccine only be used in adults 55 years of age and older due to concerns over a rare risk of blood clots that’s increasingly showing to be possible across a range of age groups.

Health Canada has authorized the AstraZeneca vaccine for use in Canadians aged 18 and over.

Contrary to the widespread messaging from governments and public health officials to get the first vaccine offered to you, Deeks said NACI continues to “preferentially recommend authorized mRNA COVID-19 vaccines due to the excellent protection they provide, the absence of a safety signal of concern, and the acceptability of the vaccines by people in Canada.”

NACI’s latest guidance was swiftly condemned by Saskatchewan ICU physician and professor Dr. Hassan Masri who, on CTV News Channel, said NACI’s messaging around potentially waiting for a different vaccine was disappointing and “extremely damaging.”

“They talk about the risk perception, and you know what your individual risk is, the reality is… there isn't an area in Canada really, aside from the Atlantic bubble, where the situation is really low risk, where you could afford to wait for your vaccine,” he said. “These recommendations don't match reality.”

RISKS VERSUS BENEFITS

Deeks said NACI’s guidance change reflects the ongoing evolutions in Canada’s vaccine rollout, factoring in the number of and types of available of vaccines, their efficacy, and the reality of the pandemic while seeking to balance any health risks with the benefits of the added layer of immunity protection against serious COVID-19 illness.

Specifically, NACI says it weighed the benefits of receiving an early dose of the AstraZeneca vaccine to the risk of serious complications from COVID-19 as is being seen in more cases where Canadians have contracted a COVID-19 variant of concern, as well as to the risk of experiencing a vaccine-induced immune thrombotic thrombocytopenia (VIITT).

Deeks said this risk varies in different parts of the country, based on the local pandemic and rate of spread. So, it may be more advantageous for someone younger in a hotspot community to be given access to an AstraZeneca shot than in another region where case counts are low.

“What we want is to vaccinate Canadians as quickly as possible. However, if you are in an area where there is no COVID transmission, if you have no contact with the outside, or if you're able to shelter through public health measures, then there is a possibility to wait for the mRNA vaccine,” said outgoing NACI Chair Dr. Caroline Quach-Thanh suggested. “But if you do want to get a vaccine earlier, I think AstraZeneca is a safe way to be protected.”

Dr. Masri had a different message: “As a physician, and as someone who's working in the ICU, my advice would be: Take the vaccine and take the first vaccine that's offered to you.”

This is now the third time the committee has suggested new age groups for whom the AstraZeneca vaccine should be offered to. Previously NACI had recommended that Canadians 65 and older receive prioritized access to the Pfizer-BioNTech and Moderna shots due to the limited efficacy data of the AstraZeneca vaccine in older populations.

Over the course of NACI’s evolving advice, Health Canada has maintained that the AstraZeneca vaccine is safe and effective, and that any potential risks are greatly outweighed by the benefits of being immunized against COVID-19.

So far, four cases of rare blood clotting incidents have been reported in Canada after receiving an AstraZeneca shot.

Overall, VIITT is estimated to occur in one in every 100,000 to one in every 250,000 people vaccinated with the AstraZeneca COVID-19 vaccine.

REGIONS TO CONSIDER ADVICE

NACI was set to release the updated advice based on the latest evidence on Tuesday, but postponed its announcement “in order to further validate its data analysis.” On Friday, Deeks said that the panel opted to postpone after receiving new provincial data that looked at new disease risks in hotspots and variants, not due to any new safety concerns.

While past rounds of NACI guidance were swiftly adopted by provinces, it remains to be seen whether provinces will move their goalposts again based on this latest report. NACI’s guidance is meant to be suggestions and it remains up to each province and territory to determine how it wants to prioritize access to the current supply. Early indications are additional shipments may be needed before access to the AstraZeneca vaccine is expanded. 

In a statement, the Council of Chief Medical Officers of Health said that NACI recommending lowering the age threshold for the AstraZeneca vaccine has “provided jurisdictions with considerations that will help us determine how to achieve the greatest benefits from the use of this vaccine.”

Amid reports of AstraZeneca doses sitting unused on pharmacy shelves because of vaccine hesitancy that medical experts have in part attributed to due to the changing guidance around blood clot risks, several provinces moved to lower the eligibility age to 40 or 45 in recent days.

This has allowed younger adults to book appointments, including Prime Minister Justin Trudeau who received his first shot on Friday alongside his wife, Sophie Gregoire Trudeau.