It’s World Immunization Week, which doesn’t ordinarily mean much in this part of the planet where vaccines for a raft of common diseases are readily available. But the coronavirus has changed all that.

The deadliest public health crisis since the Spanish flu has prompted discussions on new approaches to vaccine development and mass immunization on a global scale. The science used to develop COVID-19 vaccines will help fast-track the development of other vaccines to fight future pandemics.

But the coronavirus has also unleashed a new wave of vaccine hesitancy over the possible side effects and safety of vaccines.

Vaccine hesitancy was an emerging issue before the coronavirus. The Canadian Immunization Research Network found misinformation to be the most significant cause of mistrust and fears around immunization.

That has been the case in Canada where the AstraZeneca vaccine has been the subject of some bad PR over the rare incidence of blood clots, despite the fact there have been only a handful of cases in Canada and the vaccine has been the least administered of the big three in use in Canada.

So far 24 percent of Canadians have been vaccinated. More than 17 percent have received the Pfizer vaccine. Around four percent have received the Moderna vaccine. Only 1.6 percent have received the AstraZeneca vaccine. Another just over one percent have received the Covishield vaccine.

A recent survey of social media traffic released by the Ontario Medical Association suggests anti-vaccine conspiracies are also on the rise in Ontario. 

But the roots of vaccine hesitancy in Canada run deeper than that.

The Canadian Community Health Survey conducted by Statistics Canada late last year suggests vaccine hesitancy cuts along racial and socio-economic lines. The communities that occupy employment sectors most affected by the virus are also among the least likely to be vaccinated. 

Members of Black and Latin American communities, for example, reported that they were less willing to be vaccinated—56 and 66 percent, respectively—than the population in general. 

Politics also plays a part in vaccine hesitancy. According to the latest Angus Reid survey released Monday, Canadians who voted for the Conservative party in the last election are five times less likely to be vaccinated.

You can never be too careful when it comes to protecting public health. Government messaging—and transparency—are important to public confidence. But in Canada’s case, precautions taken with the AstraZeneca vaccine early on has also contributed to vaccine hesitancy—or at least vacillation—according to Angus Reid.

This week, the federal government’s National Advisory Committee on Immunization (NACI) released the vaccine for use in adults 30 and older after pausing and restricting its use to adults over 55 a couple of weeks ago.

NACI stressed at the time that the move was “precautionary,” and that the vaccine is safe. Less reported has been the fact the vaccine seems to retain meaningful effectiveness with the U.K. variant of the virus. But as in Europe, government and public health officials are erring on the side of caution, despite the possibility of serious side effects being very rare, something like one in a million.

While the somewhat mixed messaging that’s resulted has contributed to vaccine hesitancy, it’s a double-edged sword for public health officials who worry that the fallout from keeping information from the public, no matter how inconsequential the risks of vaccines, could contribute to higher incidence of hesitancy.

It seems to be working. Canadians seem to be slowly losing their aversion to AstraZeneca. The percentage that say they would be willing to be vaccinated with the vaccine has jumped 11 percent since early April, per Angus Reid’s data.

A third wave of the virus and the growing emergence of more contagious variants of the disease have seemingly tipped the scales. But almost half of Canadians (48 percent) still say they’d prefer to wait for a different shot rather than getting in line for AstraZeneca.

The company was in the news again this week after an inspection of a plant where its vaccine is being produced in Baltimore was cited for unsanitary conditions by the U.S. Food and Drug Administration. Canada received some 1.5 million doses of AstraZeneca’s vaccine from that plant, but Health Canada says the shipments passed safety inspection at the border

Public confidence in Johnson & Johnson’s vaccine produced at the facility has come under scrutiny after it was paused and restarted for use in the U.S. last week over a possible link to blood clots. Health Canada says none of the shipments of the vaccine expected in Canada later this week were manufactured at the plant. But Johnson & Johnson’s vaccine now rates as the least trusted in Canada, according to Angus Reid, despite its previously reported “one and done” advantage over other vaccines, which require two shots.

More recently, Pfizer’s vaccine, which is seen as the gold standard, has come under the microscope in Israel over reports of some recipients experiencing minor inflammation of the heart. But that development has seen comparatively less media coverage so far. 

Whatever the risks of vaccines, and so far those have been negligible, the dangers posed by the coronavirus are far more hazardous to human health.