The National Advisory Committee on Immunization (NACI) has changed its advice on the Oxford AstraZeneca vaccine and now says the shot is safe for adults age 65 and older.

Medical experts advising the federal government said they have considered three real-world studies into the two-dose vaccine’s efficacy.

The studies showed the vaccine to be effective in preventing severe illness and hospitalization among seniors, the NACI said.

When Health Canada approved the vaccine last month, the NACI initially said vaccines using mRNA technology by Pfizer-BioNTech and Moderna should be prioritized for people older than 65 since there was more evidence of greater efficacy with that age group.

The NACI still recommends the older age group be prioritized for mRNA-based vaccines.

“While all available vaccines in Canada are safe and effective, NACI still recommends that in the context of limited vaccine supply, initial doses of mRNA vaccines should be prioritized for those at highest risk of severe illness and death and highest risk of exposure to COVID-19,” they wrote in revising the recommendation.

At B.C.'s COVID-19 briefing yesterday (March 15), provincial health officer Dr. Bonnie Henry said that the initial shipment of the AstraZeneca vaccine will be used in B.C. for workers in industries that are considered at high risk for transmission, including at food processing plants, agricultural operations, and industrial camps.