VANCOUVER -- A B.C. care home where many residents and staff had received a COVID-19 vaccine is managing a new outbreak of the disease, prompting the province's top doctor to remind locals the vaccine won't stop all transmission.

Dr. Bonnie Henry announced during her COVID-19 briefing Monday that Cottonwoods Care Centre in the Interior was a new outbreak of the coronavirus. Henry explained all residents and staff at the facility had been offered the vaccine and said there was "a very high uptake." 

In fact, some at the Kelowna care home had even received second doses of the vaccine before the province extended the interval between the two shots to four months.

"This serves to remind us that while we are very confident that vaccine is very effective, and prevents particularly severe illness and death, it doesn't necessarily mean that all transmission will be stopped," she said.

"We need to be mindful right now when we still have high levels of transmission in our communities, how important it is to continue those precautions particularly with older people and in care homes."

CTV requested an interview with Interior Health medical health officer Dr. Sue Pollock, but were told she was not available. In an emailed statement, Dr. Pollock said it's hard to know how the virus came into the facility, and though the source is being investigated through contact tracing, it's possible they may never know.

"We have 11 cases among residents and two staff," she said. "Eight of the cases had at least one dose, and five were not immunized for a variety of reasons."

Dr. Pollock said some of the people who were vaccinated only received their shot recently, and noted it can take two to three weeks to build up immunity.

"Among the current cases, all of the individuals are doing well," she said, and added immunization teams have returned to the site. "We are offering the vaccine again to all staff and residents who may not have had it the first time and some who were hesitant before will accept it now."

UBC adjunct professor in the division of infectious diseases Horacio Bach said while immunity levels following a shot may differ depending on the individual, vaccines have been shown to reduce serious illness and hospitalization. He added the more people who get immunized, the harder it will be for the virus to spread.

"Definitely the transmissibility of the disease will go down because the virus will find some problems (getting) a new host," he said, and noted that's especially important in the fight to keep new variants from cropping up. "Every person that is infected with the virus may potentially produce a new variant."

According to data from the BC Centre for Disease Control, 82 per cent of residents at the centre had received a vaccine by Feb. 15. Dr. Pollock said the rate of immunization is lower amongst staff, about 65 per cent. 

The facility, run by the health authority, has 221 long-term care beds.

Outbreak protocols are in place at the care centre, including a pause in all visits, the health authority says.

As of Monday, 333,327 doses of COVID-19 vaccines had been administered in the province. Residents and staff of long-term care homes were prioritized in Phase 1 of B.C.'s vaccine distribution plan. Now in Phase 2, health authorities began booking appointments Monday for residents aged 90 and older and Indigenous people aged 65 and older. 

Henry said Monday there are still 18 active outbreaks in health-care facilities across the province.

With files from CTV News Vancouver's Kendra Mangione