VANCOUVER -- Because of the current Pfizer shortage, many British Columbians who got that vaccine for dose one will be offered Moderna at their second appointment.

The two vaccines are considered interchangeable. But some first dose Pfizer recipients are walking away from their second shot booking when they’re told they’ll be given Moderna.

“There have been some isolated incidents where people have chosen not to receive their second dose at the clinic that day. From what I have heard so far, there has been discussions and people have left,” said Mike Benusic with the Island Health Authority.

“It certainly is a fraction of the people who come to the clinics, but it’s who we hear about,” he said.

Their decision to turn down a dose of Moderna has doctors shaking their heads.

“I’m surprised to find they are disappointed or angry. Moderna is equal to Pfizer, bar none. So I think it’s the way its been branded and educated,” said Vancouver family physician Dr. Madhu Jawanda, the co-founder of the “This is Our Shot” campaign.

Dr. Gerald Evans, an infectious disease specialist at Queens University, agrees.

“It is this availability bias, where (people think to themselves) wow, I just heard lots about Pfizer. Every time I read something, it’s about Pfizer. Every time something is mentioned, it’s Pfizer. So people really get used to the idea this must be the best vaccine, because I hear about it a lot,” said Evans.

In reality, the two vaccines are virtually identical. “The only thing that differs is the size of the dose, in Pfizer it’s a smaller dose of 30 micrograms and in Moderna it’s 100 micrograms,” said Evans, adding “I think its really important we tell people this is the same vaccine.”

Both doctors believe experts should be on hand at each immunization clinic to speak to people who are hesitant to get a second dose of Moderna, to inform them about the interchangeably of the two vaccines, and explain why Pfizer isn’t being offered right now.

“There have been a few instances of people getting angry if their brand isn’t available, and I certainly do ask people to be understanding with the staff at the clinic,” said Benusic. “If there are concerns, you know you’re not required to receive it that day. You can take your time, think about it, read about it, re-book your appointment at that time.”

Dr. Jawanda hopes those people will come to the realization that Moderna is just as good as Pfizer for dose two, and mixing and matching them is perfectly safe.

“They are both mRNA vaccines they work the same way, the efficacy is the same, everything is the same,” she said. “So please, don’t hesitate. Get whatever is offered to you.”