The Chief of Staff at Windsor Regional Hospital says there's no reason to believe the Pfizer and Moderna COVID-19 vaccines are not interchangeable.
Dr. Wassim Saad says both of the m-R-N-A vaccines have the exact same ingredient list.
Health Minister Christine Elliott is assuring residents who got a first dose of the Pfizer COVID-19 vaccine that it's safe to take the Moderna vaccine for their second shot.
Supply issues involving the Pfizer vaccine mean that those going for their second shot could end up receiving the Moderna vaccine.
Dr. Wassim Saad told AM800's The Morning Drive he agrees with the province that there is no difference between the vaccines, but he understands that people will want to be informed when it comes to mixing vaccines.
"Obviously there's the principle of informed consent, where people want to know what they're getting in their arm and I completely understand that and that's exactly what I would tell my patients," he says. "But I would tell them is that you are getting a m-N-R-A vaccine for your second dose and a lot of this is driven by supply."
Saad says we are in a race against time to get as many people fully vaccinated to get ahead of the Delta variant.
"The science is very clear here and we have to understand that Moderna is not an inferior product, number one. Number two, vaccines are interchangeable. Since the beginning of the history of vaccinations, they have always been interchangeable," he adds.
The province says it's using a large supply of Moderna doses for many appointments because its shipment of Pfizer vaccines for the week has been delayed by a few days.
That means residents may end up with a different m-R-N-A shot for their second dose -- but federal officials say there is no important difference between the Pfizer and Moderna vaccines.
The Windsor-Essex County Health Unit announced Monday that due to supply issues, anyone going to receive their second shot of the COVID-19 vaccine would be receiving Moderna at any of the mass vaccination clinics in the area.