The association representing Ontario pharmacists says roughly half of people looking to get a Pfizer vaccine are rejecting the Moderna shot if they are offered that instead.
"They may cancel their appointment. They may walk out," said Justin Bates, CEO of the Ontario Pharmacists Association.
"That's creating a significant challenge," said Bates, as pharmacists also have to deal with combative patients who want to shop around for vaccines.
Many people did the same thing last spring when they questioned the safety of Moderna or mixing vaccines during the rollout of second doses.
Now, they have less choice in the matter because many public health units are reserving Pfizer for younger people because there's now a greater supply of Moderna. In Toronto, Durham and Waterloo regions, people aged 30 and up will only be offered Moderna.
Last fall, the Ontario government recommended people between 18 and 24 receive the Pfizer vaccine due to a "mild risk" of the rare heart condition myocarditis "out of an abundance of caution." Pfizer is also only being offered to those aged 12 to 17.
Jason Chomik opted to get Moderna for his third shot on New Year's Day, even though he put off two appointments before getting Pfizer for his second dose. He says the surging Omicron variant finally prompted him to make the move.
"If the numbers hadn't been climbing as rapidly as they are now, I probably would have waited," he said.
"I'm glad I got the booster but I'm still concerned around the long-term effects of mixing the vaccines."
'They only want Pfizer'
Despite public messaging that mixing vaccines is safe, as is Moderna, many are still reluctant to get it. Aside from pharmacies, health workers at other vaccine clinics are seeing this, too.
"When they sit down in the chair, they immediately confirm [they're getting Pfizer] with me," said Allan Grill, who has been administering vaccines in York Region, north of Toronto, and is chief of family medicine at Markham Stouffville Hospital.
"They only want Pfizer."
Grill, along with many infectious disease experts, have long maintained the risk of getting infected with COVID-19 is far greater than any risk associated with getting any of the vaccines.
"Omicron is spreading like crazy and people are getting sick," he said.
Even Ontario's Chief Medical Officer of Health Dr. Kieran Moore made a plea during his briefing on Thursday.
"I, too, got Moderna as my booster," he said.
"The latest evidence demonstrates the protection provided by the Moderna vaccine, particularly for older individuals, is very robust."
More brand awareness
Bates said there's more brand awareness around Pfizer's vaccine, especially since many got it for their first or second dose. He also said the pandemic continues to change policy with time and new research.
"People aren't used to seeing science evolve in real time," he said. "And changing public perception is the hardest thing to do."
Toronto's Medical Officer of Health Dr. Eileen de Villa said the city is "doing everything we can" to make sure people are aware vaccines are safe and effective.
"In fact, there are some studies showing a particular benefit to those who receive the Moderna vaccine and its effectiveness against the Omicron variant."