VANCOUVER -- Provincial health officers have eased some COVID-19 restrictions in B.C., but a new one is in place for an upcoming holiday.

Bars and restaurants will have to stop serving alcohol at 8 p.m. on St. Patrick's Day.

The holiday, which falls on a Wednesday this year, is typically one of the biggest nights of the year for bars.

But Dr. Bonnie Henry says the move is meant to protect staff and customers, and to prevent an explosion of new cases in the days and weeks to come, as seen around other holidays last year. Similar rules were put in place in B.C. on New Year's Eve.

The workers' compensation board will have inspectors out in force on March 17.

"Sometimes when businesses get busy, when a restaurant, as an example, gets busy, people can let their guard down, and that's what we don't want to happen," WorkSafeBC's Al Johnson said.

"A reminder to stay true to your COVID safety plans, make sure you're following the plans to the letter and be vigilant.:

In the last year, the board has conducted more than 20,000 COVID-related inspections, and found about 2,200 violations.

The one-day restriction was announced during an update Thursday on modelling data in the province.

The provincial health officer said findings suggest the vaccine has been effective in preventing about 80 per cent of COVID-19 cases in B.C.

The vaccine rollout plan entered Phase 2 at the start of the month, and Henry opted this week to loosen some restrictions ahead of March break.

Prior to her announcement, residents of B.C. were permitted only to socialize with members of their own household (family or roommates), with exceptions only for people who live alone.

But now they can gather with as many as 10 people, provided they stay outside during their meetings.

Henry cautioned against being lulled into a false sense of security, however, noting that health officials are watching closely as variants of concern continue to be detected in the province.

The top doctor said these variants make up less than 10 per cent of known cases in the province, compared to 40 per cent in Ontario Thursday, but the rate is increasing, and public health guidelines including wearing a mask and regular handwashing should still be followed.