VANCOUVER -- B.C. added 357 new cases of COVID-19 and three related deaths over the last 24 hours, health officials announced Thursday.

The last time B.C. recorded a lower number of new coronavirus cases in a single day was on Feb. 16, when the province saw 302 new infections.

Thursday's total is also the first time B.C. has seen fewer than 400 cases in a day since March 8, when 385 new cases were added to the total.

The latest numbers bring B.C.'s rolling seven-day average of daily new cases 449.

The province has now seen 140,953 cases and 1,661 deaths since the pandemic began.

Currently, there are 4,636 cases active in the province. A total of 331 people are fighting COVID-19 in hospital, 113 of them in intensive care.

Provincial health officer Dr. Bonnie Henry and Health Minister Adrian Dix provided the latest numbers during a live briefing with Premier John Horgan in Victoria.

The trio also announced B.C.'s plan for immunizing young people between the ages of 12 and 17.  

As of Thursday, B.C. has administered 2,687,360 doses of COVID-19 vaccines, Henry said. Of those, 138,906 were second doses. That means slightly more than 58 per cent of eligible adults in the province have received at least a first dose, according to Henry.

The provincial health officer also provided data on the effectiveness of the Pfizer and Moderna vaccines among those over age 70 in B.C.

"After three to four weeks, so 21 to 28 days, with a single dose, a person's risk in our community of transmitting SARS-CoV-2 (the virus that causes COVID-19) has been reduced by 70 per cent," Henry said. "This means we prevent over two of three new infections."

She said the numbers show that B.C.'s vaccine program is "highly effective," but also serves as a reminder that vaccines need time to take effect.

Knowing this, it's important to "stay the course" on restrictions, Henry said.

Horgan began Thursday's news conference by reminding people that travel restrictions and other rules that are part of B.C.'s "circuit-breaker" are scheduled to remain in effect through the end of the May long weekend.

"As a province, we've come a great distance over the past 15 months," the premier said. "We have a little ways to go yet, but we're so close."

He said he would be joining Henry and Dix for another announcement on B.C.'s plan for easing restrictions on Tuesday.

"Now is not the time to let up as we're doing so well and getting so far ahead," Henry added. "We all need to stay local, stay small and continue to use all of our layers of protection."

Henry announced one new outbreak of COVID-19, at Chartwell Carlton Care Residence in Burnaby. She also announced the ends of two other outbreaks, leaving the province with four ongoing outbreaks in care homes.

In a separate statement earlier in the day, Fraser Health announced that one resident and one staff member at Carlton had tested positive for the coronavirus. 

The provincial health officer also announced that some outbreaks that had occurred in recent months had not been publicly reported, something she said would be rectified on Thursday.

"It has come to my attention in the past week that there are several outbreaks in assisted living that were responded to over the past number of months and were managed aggressively as we do for all outbreaks, but have not been reported or posted in our outbreak reports," Henry said.

She specifically mentioned two outbreaks in the Vancouver Coastal Health region, at Terraces on Seventh and Chalmers Lodge in Vancouver.

"Full action was taken by local public health and by my public health colleagues to manage with those facilities, but they have not yet been included," Henry said. "We want to make sure that all of these outbreaks are in our outbreak reports, and they will be added today for transparency." is streaming the news conference LIVE NOW.