HALIFAX -- As the science around vaccines evolves so, too, is the advice on how to use it.

Nova Scotia's chief medical officer of health now recommends people who had a first dose of AstraZeneca not take it as their second shot.

"I'm now recommending that anyone who got a first dose of AstraZeneca can get a second dose of an mRNA vaccine," says Dr. Robert Strang.

At the beginning of the vaccine rollout, Nova Scotians were advised to take the first available appointment regardless of the type of vaccine, that's what many did.

"When we did get a booking in, it was AstraZeneca and the next the recommendation came out to not take the AstraZeneca," says Frank Grant of Yarmouth.

After weighing the risks, Grant and his wife kept their scheduled appointment, and they don't regret it. In fact, Grant says they'd take the somewhat controversial vaccine again.

"We did receive the AstraZeneca, first dose and we are planning to get the AstraZeneca second dose if it's available to us."

Dr. Strang says the province has about 2,000 doses of AstraZeneca in storage right now.

He says there is also an ample supply of Pfizer for those who want to switch their vaccine.