BARRIE, ONT. -- Phones have been ringing this week at homes across Simcoe County and Muskoka as doctors call patients ready for dose two of the AstraZeneca COVID-19 vaccine.

Residents who got an AstraZeneca shot between March 10 and March 19 are eligible, following a provincial pause on that vaccine for first shots.

The South Georgian Bay Ontario Health Team plans to administer 560 second doses of AstraZeneca at a drive-thru clinic in Collingwood Saturday.

Only 300 first doses were administered at the clinic in March, but a spokesperson explained many people got their initial doses at pharmacies outside the region.

Complete information on Simcoe Muskoka's vaccine rollout is available here.

On Wednesday, the federal health minister urged provinces to share doses of AstraZeneca if they can't be administered before expiry.

There is an indication that more Ontarians will soon qualify for second doses of other vaccines.

Speaking before York Regional Council Thursday morning, York's Medical Officer of Health, Dr. Karim Kurji, revealed that the provincial government plans to shorten intervals for second doses, currently set at 16 weeks.

"They have given us the heads up that they hopefully will move in that direction as of next week, with the over 80 group and then subsequently moving down to the over 70 age group," Kurji said.

Kurji is still working through logistics to come up with a rollout that is fair and minimizes confusion.

Family doctors are also taking on a greater role in administering vaccines. Primary care practitioners in Simcoe Muskoka are part of a pilot project to administer shots of Moderna. The Simcoe Muskoka District Health Unit could not immediately say how many doctors part of the test or say when the effort might be expanded.