British Columbia's top doctor says the province is extending the interval between the two doses of the Pfizer-BioNTech COVID-19 vaccine.

Dr. Bonnie Henry says further delays in the production and delivery of the vaccine over the next two weeks prompted health officials to extend the time period between the shots from 35 to 42 days.

She says about 60 per cent of the more than 119,000 doses of COVID-19 vaccine administered in the province so far have been used to protect residents of long-term care homes.

Dr. Henry provided an update on B.C.'s vaccine supply on Monday while reporting 26 more deaths linked to the illness and 1,344 new cases of COVID-19 diagnosed over the last three days.

She says the curve of the pandemic in B.C. has plateaued at around 500 cases a day, which is too many, particularly if transmission of several faster-spreading variants of the illness increases in the province.

The latest situation report posted by the B.C. Centre for Disease Control shows three confirmed cases of the COVID-19 strain first identified in South Africa and six of the variant first found in the United Kingdom.