TORONTO -- More Ontarians are eligible to book their second dose of a COVID-19 vaccine through the provincial system today.

Those aged 70 and older, as well as people who received their first dose of an mRNA vaccine on or before April 18, can now book their second shot on the province's website or through its phone line.

The expansion comes as Ontario nears a vaccination milestone: 10 million doses administered.

On Sunday, the province reported that it had given out more than 9,992,000 doses, with more than a million Ontarians fully vaccinated.

Also today, the province's incoming chief medical officer of health begins his transition to the new role.

Dr. Kieran Moore will start working with the current top public health official, Dr. David Williams, before taking over in a few weeks time.