VANCOUVER -- Health officials in British Columbia say adults under the age of 55 will no longer be receiving the COVID-19 vaccine made by AstraZeneca for the time being.

The update comes after a similar recommendation from the National Advisory Committee on Immunization, which was made public Monday morning.

Speaking at a news conference in the afternoon, B.C.'s top doctor said the province will follow that recommendation, at least for now.

Dr. Bonnie Henry said the province will not be giving adults younger than 55 the AstraZeneca shots "for the next few days."

"Over this past week, a signal was detected in younger people in Europe using the AstraZeneca vaccine," she said.

The doctor described the issue as a "very rare condition, with tens of millions of doses of this vaccine being used" and very few instances being reported. She said there have been fewer than 30 confirmed cases identified in the world of the condition, called vaccine-induced prothrombotic immune thrombocytopenia.

"It's a serious condition and could lead to serious outcomes," she said, so the province will suspend its use in younger recipients.

B.C. Premier John Horgan said that pausing the administration of the AstraZeneca vaccine won’t slow down the province’s roll-out out of vaccines by age cohorts.

“We had not calculated (the use of) AstraZeneca into any of our thinking with respect to age cohorts,” he said. “The Pfizer vaccine and the Moderna vaccine are coming in large amounts in the next number of weeks.”

Infectious Disease Expert at the University of British Columbia, Dr. Srinivas Murthy says there are other alternative vaccines available.

“While yes, we won’t have the ability to rapidly vaccinate like we would have with the AstraZeneca. But the fact that we have Phizer and Moderna coming in fast over the coming weeks – suggests there is some flexibility,” he said.

The temporary pause of AstraZeneca has many wondering if this will stall B.C.’s roll out plan, as 300,000 frontline workers, including teachers, were scheduled to receive the AstraZeneca shot on April 1st.

“I am worried that we may not see the vaccination program for essential workers as was laid out. I certainly hope that does not happen,” said Terry Mooring, President of the B.C. Teachers Federation.

Based on a tweet posted by the superintendent of schools in Surrey, B.C., it appears some front-line workers outside of the province's age-based schedule were contacted earlier in the day Monday and told they'd be given a different vaccine.

Dr. Bonnie Henry said Health Canada has reached out to the AstraZeneca manufacturer for more information on the “risk-benefit profile" and what it means for Canadians.

She expects to have more information in the next two or three days.

And she anticipated questions from those who've already had a dose of the vaccine in question.

"If you have received the AstraZeneca vaccine and it's more than 20 days since you've received it, there are no concerns. If you have received the AstraZeneca vaccine and have developed symptoms that are concerning, such as headaches or swelling… you can seek medical attention."

Henry said it's unlikely there will be any cases of the rare condition in Canada, but those with possible symptoms can undergo testing.

"The other thing that is important (is) we have time to understand how this will affect second doses in people who have received the AstraZeneca vaccine. It is very likely that second doses will be available but we have time between now and three to four months to understand the implications of this," she said.

With files from CTV News Vancouver's Mary Cranston