BARRIE, ONT. -- Ontario declared Simcoe Muskoka one of the province's Delta variant hot spots, accelerating timelines to book second vaccines for many residents.

Starting Wednesday, residents who had their first mRNA vaccine on or before May 30 can book their second vaccine.

The province also said adults 18 and older who got a shot before May 31 would be able to book their second dose starting June 28.

Children 12 to 17 will be eligible to book their second Pfizer shot starting sometime in August.

Additionally, residents who received AstraZeneca as their first dose will be eligible to book their second dose at an eight to 12-week interval.

The news comes as the region reports its lowest COVID-19 daily case counts in months. On Thursday, the health unit logged 12 new infections, and nine the day before.

Still, the Simcoe Muskoka health unit has confirmed 18 local cases identified as the more transmissible Delta variant as of Thursday.

The health unit has an additional 676 cases that screened positive for a variant of concern but require further testing to identify the strain.

The region's medical officer of health said the Delta variant was about 50 per cent more contagious, adding residents with only one dose of the vaccine are believed to be less protected against it.

"The Delta variant, that is increasing in prevalence, and we expect to become the dominant as a strain, really requires a second dose of immunization to be well-protected," said Dr. Charles Gardner during a live COVID-19 update.

The health unit anticipates more vaccine shipments this week. "We will be receiving some 20,000 doses to our area of Moderna, on top of the 30,000 doses of Pfizer," Gardner noted.

To date, 62 per cent of Simcoe Muskoka residents received one dose of the vaccine, while 12 per cent have had both.

There are currently 10 regions considered hot spots, Toronto, Peel Region, Porcupine, Waterloo, Wellington-Dufferin-Guelph, Halton Region, Hamilton, Durham and York Region.