News Ontario opening accelerated second dose appointments for youth aged 12 to 17 SHARE ON: Casey Kenny, staff Friday, Jul. 2nd, 2021 Supplied by the Province of British Columbia Children and youth aged 12 to 17 can soon book their second COVID-19 vaccine dose faster. Starting 8 o’clock Monday morning, those in that age bracket across Ontario will be eligible to book an accelerated second dose appointment to receive the Pfizer vaccine. They can make their appointment through the provincial booking system, directly through public health units that use their own booking system, and through participating pharmacies. During the week of June 21st, Ontario administered more than one million vaccine doses in four days.