No, you shouldn’t wait for a better vaccine


by Raywat Deonandan

Mar 15, 2021

This article was published in The Ottawa Citizen under the title, “Deonandan: No, you shouldn’t wait for a better vaccine” on Mar 15, 2021.

Scientists were rendered giddy by the data published by Pfizer and Moderna for their COVID-19 vaccines. Each showed 94-95% efficacy! Canadians now have access to formulations from Astra Zeneca and Johnson & Johnson, as well. But their efficacy scores, while very good, are nonetheless slightly lower than those of Pfizer and Moderna So some Canadians are choosing to wait for “a better option” when given the chance to receive an AZ or J&J shot immediately.

The WHO’s Dr Mike Ryan said it best when advising his own mother: “Whatever vaccine they show up with, you take it. Because that is the best decision you can make on that day for your health.”

The AZ vaccine has received particular scorn. Reports that some European countries had suspended its use in the wake of 30 thromboembolic events (serious blood clots) are scary to some Canadians.

The European Medicines Agency has stated that there is no indication that the vaccine caused these events. Health Canada concurs. This is not surprising, given the tiered manner in which vaccines are distributed. The elderly are the first to be inoculated. But the elderly are also the most likely to experience a vast array of medical issues unrelated to vaccination.

As the old adage entreats, correlation is not always causation. Hence, investigations are needed to assess whether the vaccine is the likely cause of adverse events. It’s why decisions by nations to suspend treatment are merely precautionary tactics while those investigations occur.

But even if there were a causal relationship between the AZ vaccine and clotting events, 30 cases out of 5 million European recipients amounts to a vanishingly small statistical risk –0.0006%–  smaller still by a couple of orders of magnitude than the actual risk of serious clots in the general public, which is estimated by Thrombosis Canada to be about 0.02%. By this math, vaccine recipients are at less risk of clots  than are the non-vaccinated.

You know what does cause serious clots? COVID-19. Vaccines prevent COVID-19. In fact, all of the vaccines available to Canadians are excellent at preventing serious COVID disease, and –according to both clinical trial and “real world” data– all have extraordinarily high effectiveness in keeping injected people out of the hospital and out of the morgue.

And is that not the point?

When offered any of the COVID vaccines okayed by Health Canada, we should readily and gratefully accept whichever formulation is offered, for at least three reasons.

First, safety and efficacy are high in all of them. It is incorrect to compare their clinical trial efficacy scores head-to head, as each was trialed on different populations and at different times when different variants were circulating. But real world data suggest that effectiveness is actually comparable across the board. Direct comparisons of Pfizer with AZ on the UK population, found that one dose of either vaccine is 80% protective against hospitalization in those over 80, starting 14 days after injection.

Second, we must remember that the goal is not necessarily to get the best immunity for the individual eventually, but to get “good enough” immunity in a maximum number of people as soon as possible. In this way, population immunity milestones can be reached earlier, the toll of a third wave can be lessened or avoided, society can stay open, and normality is attained early.

None of those things happen if individuals choose to wait months for a preferred vaccine. If population health is achieved, then all individuals win. But if only some individuals win, then population health is not achieved.

Third, every day spent unvaccinated is a day in which one might become infected, get seriously ill, and possibly even die. It is not rational to unnecessarily prolong that period of vulnerability hoping for slightly better immunity weeks or months down the road, not when one can accept considerable immunity now.

Remember: if enough people accept adequate immunity, then community transmission falls quickly, and the risk to everyone diminishes substantially, such that the need for perfect immunity through a better vaccine is obviated.

The bottom line is this. If you get a chance to receive a COVID vaccine, even if it’s not the one you were hoping for, take it anyway. It’s your –and our—best hope of getting out of this soon and without more suffering.


Raywat Deonandan, PhD, is an Epidemiologist and Associate Professor with the Faculty of Health Sciences at the University of Ottawa.