ST. JOHN'S, N.L. -- Newfoundland and Labrador is extending the interval between the first and second doses of the COVID-19 vaccine to four months.

Chief medical officer of health Dr. Janice Fitzgerald said Wednesday the change will see nearly 40,000 more people vaccinated with a single dose by the end of March.

"Real-world evidence is now emerging and shows that the first dose of COVID-19 vaccine offers protection for a longer duration," Fitzgerald said. "It will ... help to prevent symptomatic disease, hospitalization and deaths during this most crucial time of higher disease prevalence and limited vaccine supply."

Fitzgerald's announcement preceded an updated recommendation issued late Wednesday by the National Advisory Committee on Immunization, which said the second dose of COVID-19 vaccine could be given up to four months after the first to maximize the number of people benefiting from a first dose.

British Columbia had raised eyebrows Monday when provincial health officer Dr. Bonnie Henry announced her province would delay the second dose of the Pfizer-BioNTech and Moderna COVID-19 vaccines by up to four months.

The previous guidance from the advisory committee said there should be no more than six weeks between doses of the Pfizer-BioNTech and Moderna vaccines, and no more than 12 weeks between doses of the Oxford-AstraZeneca vaccine.

Newfoundland and Labrador is still reeling from a COVID-19 outbreak that spread rapidly through the St. John's metro area in mid-February. The outbreak prompted officials to cancel all in-person voting in the provincial election, which was originally scheduled for Feb. 13, and impose provincewide lockdown measures. Fitzgerald announced three new cases of COVID-19 Wednesday and said all were connected to previously identified infections.

"We've had several days in a row with only epidemiologically linked cases, and that means that our new cases are linked to previous cases," she said. "This is good news really and indicates that we are heading in the right direction."

There are 149 reported active COVID-19 infections in Newfoundland and Labrador, and 147 of those are in the eastern health region, which includes St. John's. Officials said nine people are in hospital due to the disease, including three in intensive care.

Fitzgerald said public health is expecting about 7,000 doses of the newly-approved Oxford-AstraZeneca vaccine next week. "We intend to start administering as soon as they arrive," she said, adding that the priority group for the vaccine had not yet been determined, given that officials are recommending it for people under 65. Those in older age groups will continue to be prioritized for the Moderna and Pfizer-BioNTech shots, Fitzgerald said.

This report by The Canadian Press was first published March 3, 2021.