Ontario youth between the ages of 12 to 17 who live in designated hot spots for the Delta COVID-19 variant can book accelerated second vaccine dose appointments today.Health units covering Durham, Halton, Hamilton, Peel, Porcupine, Simcoe-Muskoka, Toronto, Waterloo, Wellington-Dufferin-Guelph and York are considered hot spots for the more transmissible variant.That demographic will have the option to re-book their second doses as of 8 a.m.