The Case for AstraZeneca

 (Cecilia Fabiano/LaPresse via AP)

"[The COVID-19 immunization  effort is a] race against time. [Canada's vaccine strategy has been to act] on hearsay and not a lot of facts."

"At my last look you guys are 3.6 percent vaccinated with two doses, so just wait for the [B.1.617] variant] to rip through the Canadian population, and then the problems you've had with these very rare [blood] clotting events will look pretty insignificant." 

"My advice is get people two doses, as fast as you can and hunker down. So, for the Canadians to be out thinking about whether they should have a second dose, you know, eating marshmallows around the campfire looks a bit silly to me, frankly."

"I just think this game of waiting around for the perfect solution, while there's a massive pandemic coming in your direction -- that does not look smart to me."

"Unless you've got two doses of mRNA vaccine sitting in a back room, you need to get on and vaccinate people with any one of the four good vaccines."

"All this messing around is going to cost lives. It's a public health decision, it's not some academic game."

Sir John Bell, Regius Professor of Medicine, Oxford University

"It would seem to be quite an excellent choice to make and have a second dose with AstraZeneca vaccine, knowing that you had no issues on your first dose ... but we also want to answer a couple of questions."

"One is what is the capacity for an informed consent of individuals who may want to choose to have all mRNA vaccine as a second dose, and we want to make sure that you have that option in front of you when you're going to make that choice."

Dr.David Williams, Ontario's chief medical officer of health

As vaccination numbers across Canada rise, provinces are preparing to start looking ahead, if vaccine targets can be met    CBC

 

The use of AstraZeneca in Canada has been suspended for first doses in the provinces of Manitoba, Ontario and Nova Scotia, in uncertainty over the vaccine's rare side effect, which causes a rare blood clotting condition. Ontario has not yet decided whether it will offer those who received a first dose of AstraZeneca, to be given the same vaccine as a second dose. Alberta is hedging its bets with plans to reserve its supply of AstraZeneca for second doses. So it's a mixed bag in Canada at a time when those provinces are struggling with both the presence of more infectious variants, and a rising tide of cases.

And then there is the issue of Canada having called upon COVAX stores for its 'share' of vaccines contrary to the real and deep purpose of the vaccine-sharing plan; to distribute vaccines to developing countries resulting from developed countries having pooled contributions to the sharing-and-distribution effort. While it was legitimate for Canada to request its 'share' it's also counter-productive and morally questionable, to the purpose of COVAX; wealthy countries sharing among developing countries.

So Canada received its COVAX 'share' of AstraZeneca and in the current climate of suspicion over the rare vaccine-related blood clotting has put their use on hold. And while they're in freezers, in storage awaiting a decision over their use, Canada is now steadily receiving an ongoing contracted-for vaccine doses from Moderna and Pfizer, and Johnson & Johnson. Having extracted its due from the global alliance to distribute doses more widely in countries without the capacity to purchase volumes of their own, some of the AstraZeneca doses will be expiring.

According to Ontario's chief medical officer of health, the province is awaiting the federal government's decision on the issue of mixing and matching vaccines prior to offering second doses to AstraZeneca recipients. The hesitation over the use of AstraZeneca was spurred in early May when the National Advisory Committee on Immunization, tasked with advising the federal government with guidance on vaccine use in Canada, stated it "preferentially recommended" mRNA vaccines such as Pfizer and Moderna.

Viral vector vaccines like AstraZeneca and Johnson & Johnson's single shot, were recommended by NACI to be offered to Canadians aged 30 and older should they prefer an earlier vaccine "rather than wait for an mRNA vaccine." Exactly the kind of advice that runs counter to what Dr.Bell advises for optimum population coverage against the SARS-CoV-2 virus. According to Dr.Bell, Oxford University is currently conducting a study on mixing AstraZeneca and Pfizer vaccines and initial findings reveal that some side effects will result.

"Our experience to date is that it produces pretty severe reactogenicity, so severe that we don't think it's going to be viable. By that I mean, you get your second dose if you flip it over, you'll get really sick, so I would not advise that." Researchers found that mixed vaccine dosing schedules produced more frequent mild-to-moderate reactions after the second "booster" dose, in comparison to standard non-mixed vaccine schedules.

"The results from this study suggest that mixed dose schedules could result in an increase in work absences the day after immunization", advised Matthew Snape, associated professor in pediatrics and vaccinology at Oxford, the chief investigator on the trial.