The province’s Health Minister is justifying the province’s approach to second dose vaccine appointments.

Earlier this week, John Haggie revealed that vaccine appointments would be based on vaccine availability—meaning clinics will have both Pfizer and Moderna, but the shot administered will depend on availability.

That approach has raised ethical concerns from people, with some suggesting that people should be informed of which vaccine they’re getting before arriving at the clinic.

Haggie argues that they are offering a “safe, justifiable, and rational” approach to vaccinations.

Although officials are pushing for people to get the first type of vaccine offered to them, Haggie says that should someone not wish to receive a certain vaccine they are free to cancel their appointment and rebook.

However, he stresses, both Pfizer and Moderna mRNA vaccines are interchangeable. He says as time goes on the amount of Pfizer may increase, which will make the choice a lot easier.