SASKATOON -- As some people in Saskatchewan are preparing to get their second COVID-19 dose, there are many questions regarding if it’s safe to mix vaccines.

Epidemiologist and founder of EPI Research Inc. Cynthia Carr says it’s “very much likely” that people will receive the same vaccine for their second dose, should supply stay the same and no safety signals are risen.

“We only have a certain amount of choice in this, it’s not going to be up to us to decide if we mix and match the vaccine, it will be our scientific leadership that will tell us,” Carr told CTV News.

Carr says the vaccine was approved for use based on clinical trials using the same first and second dose.

She adds mixing vaccines isn’t a new concept and that trials are ongoing for vaccine interchangeability.

“These things happen when there’s a shortage of vaccine supplies, or there’s a new vaccine that might seem better, or in better supply.”

Carr says history shows it is safe but clear clinic protocols are needed first before it’s officially recommended to a population.

Infectious disease expert Jason Kindrachuk agrees. He says the world is weeks away from getting data from a clinical trial out of the U.K.

The Oxford Vaccine Group’s Com-Cov vaccine trial is studying the use of different combinations or approved COVID-19 vaccines for the first and second doses.

“The trials haven’t been stopped so if there was a massive safety concern, we would have likely heard something that the trial has been halted,” Kindrachuck said.

He adds science and new information is changing everyday and the world is in a “grey area” of what mixing vaccines will look like two weeks from now.

“I think rather than shopping around right now, keep your mind focused on the things you need to do to reduce transmission between yourself and others.”

He says scientifically “many of us are quite optimistic” and that we’ll be in for a “pleasant surprise.”

Vaccine hesitancy is something that could come up in the near future. On Tuesday Ont. announced it would no longer offer first doses of AstraZeneca following an increase of reports of blood clots.

Carr emphasizes AstraZeneca is being used in more countries than any of the other vaccines.

“All the information you’re hearing are based on exceedingly exceptionally rare events of over a billion people being vaccinated.”

Carr says she doesn’t want people to have fear or regret that they’ve made a wrong decision.