Ontarians 18 and older can now book a COVID-19 vaccine booster through the provincial portal, as long as it has been at least three months since they had their second shot.

But many social media users who logged in to reserve a spot this morning reported facing a virtual lineup of more than an hour.

Others said the earliest appointments they could find were more than a month away, while others reported no available appointments in their region.

The province announced Wednesday that it was expanding eligibility in an effort to bolster defences against the Omicron variant of COVID-19.

Pharmacies were able to start offering the boosters to younger adults on Friday, but now Ontarians can make appointments through the province's or a local public health unit's website.

There are also new public health restrictions in effect in Ontario, in a move Premier Doug Ford said was designed to protect against Omicron while the population gets boosters.

As of Sunday, restaurants, retailers, gyms and other indoor settings will only be allowed to open at 50 per cent capacity.

Indoor social gatherings are limited to a maximum of 10 people, while outdoor gatherings can only have 25.