Residents of Ontario are showing a strange type of brand loyalty when it comes to a particular commodity that has been flying off the shelves as of late: the COVID-19 vaccine.

A delay in shipments of Pfizer's version of the jab — which has quite absurdly become known as the the hot person's inoculation, for whatever reason — has meant that many who are receiving their second dose of vaccine in recent and coming days are getting Moderna, regardless of which company manufactured their first shot.

And with that knowledge, patients have actually been skipping out on their scheduled appointments, preferring the more in-demand Pfizer, whether due in part to ingrained consumer habits (thanks, capitalism), or misinformation and fears about mixing vaccines.

Either mRNA vaccine (Moderna or Pfizer) will be used depending on supply & age eligibility. As per NACI, both vaccines can be used safely & interchangeably for most age groups.

More info on 2nd dose: https://t.co/BWg7KvLFjv

— CAMH (@CAMHnews) June 23, 2021

The country's health experts have continued to urge people to get whichever shot is available to them as soon as they are eligible, assuring the public that it is indeed safe and can even be more effective to mix brands, which Canada's Chief Public Health Officer Dr. Theresa Tam has asked citizens to "consider as interchangable."

Canada's National Advisory Committee on Immunization (NACI) has also officially recommended that any individual who received a Pfizer inoculation go on to get either Pfizer or Moderna as their second (and vice versa), and also that anyone who received the AstraZeneca version get either AstraZeneca, Pfizer or Moderna as their final dose.

"This is not a new concept... getting the same vaccine for the first and second dose or a mixed schedule are both considered valid options, and both will count as a completed series," the organization states.

"Similar vaccines from different manufacturers are used when vaccine supply or public health programs change. Different vaccine products have been used to complete a vaccine series for influenza, hepatitis A, and others."

"Try and find the same vaccine, the same mRNA vaccine, but if you can't, for some reason, then consider them interchangeable." - Dr. Tam, on mixing and matching Pfizer and Moderna vaccines #cdnpoli https://t.co/MztMudjpza pic.twitter.com/QJComgt6p9

— Mackenzie Gray (@Gray_Mackenzie) June 1, 2021

Pfizer and Moderna both employ the same mRNA technology and are essentially the exact same product, which makes the fact that citizens continue to be heistant about mixing brands extremely frustrating for clinics experiencing cancellations as the government strives to immunize as many people as quickly as possible.

Epidimiologists called the phenomenon "a Coke and Pepsi thing" when speaking with the Star this week, adding that Pfizer's marketing and familiarity to consumers likely has a hand in the nonsensical partiality.

Toronto Medical Officer of Health Dr. Eileen de Villa has made the same point, comparing the two brands to different types of bottled water during a City press conference on Wednesday.

De Villa repeats that Moderna and Pfizer are interchangeable mRNA vaccines. Important thing is to get fully vaccinated as soon as possible to protect themselves and beat back the Delta variant threat, plus other variants yet to come

— David Rider (@dmrider) June 23, 2021

"For a long time, Pfizer was delivering a prominent amount of the vaccine we were using [in Toronto]. Had the supply situation been reversed, [we] would have happily and confidently used Moderna if it had been available in greater amounts earlier," de Villa said.

"In the end you're getting the same thing, that's the case with mRNA vaccines."