Questions about B.C.'s 3rd COVID-19 vaccine dose? Here are some answers

On Tuesday, British Columbia said it will make a third dose of COVID-19 vaccine available to the general population, becoming the first jurisdiction in North America to announce such a plan.

The rollout is scheduled to take place by May 2022,but only after the vaccine has beenoffered to groupsmore at risk from the coronavirus, including the immunocompromised, long-term care residents, Indigenous people over the age of 12 and seniors over 70.

Provincial Health Officer Dr. Bonnie Henry said the booster vaccine will be either the Pfizer or Moderna mRNA types, and will be available to British Columbians aged 12 and over who have already received their second dose.

Here's some of questions people have about the third dose and what we know:

Is the shot mandatory?

The Ministry of Health told CBCNews that the third shot is not mandatory.

Why do we need a 3rd dose?

According to Henry, immunity gained from the first two vaccinations has been shown to gradually decline over time. She said because the coronavirus and COVID-19 arenew, the optimal vaccine schedule is still being determined.

"It may be that this third dose this booster dose gives longer lasting protection that lasts for years," she said. "We know from studies done by Pfizer and Moderna around their booster doses that you get a good strong and quick antibody response when you get that booster dose."

"For many of us [the booster] will mean longer lasting protection into next year and the year after, potentially," she said.

WATCH | How booster doses can make a difference:

Booster doses 'can make a difference', B.C. health officer says

3 years ago

Duration 1:27

After seeing breakthrough COVID-19 cases in certain parts of B.C.'s population, Dr. Bonnie Henry says an extra dose can offer longer lasting protection.

Should I be concerned about mixing vaccines, or getting a 3rd variety?

Dr. Brian Conway with the Vancouver Infectious Disease Centre saysmixing vaccines is actually a good thing and that people should not be concerned.

"We now know that mixing and matching different types of vaccines may produce a more robust immune response and may produce more protection," said Conway.

"Get that mRNA vaccine that next shot when it is offered to you."

According to the ministry, it will be rare that someone gets three different shots, and only possible for those who received a viral vector vaccine (Covishield or AstraZeneca) for Dose 1, and an mRNA vaccine (Pfizer and Moderna) for Dose 2.For these people there is a small chance they will receive a different mRNA vaccine for Dose 3.

Will a 3rd dose be needed for the vaccine card?

Starting Oct.24, people in B.C. needed two dosesof the COVID-19 vaccine to be fully immunized and access some businesses, workplaces and events.

The booster shot is not required at this time to be considered fully vaccinated, according to the ministry.

At this point, shouldn't we share vaccines with countries that don't have anyyet?

Conway believes Canada should look after its own vaccine needs first before sharing with other countries.

"No one gets it right if we all get it half right," he said.

"Our responsibility as a nation and as Canadians is that if we have any excess vaccine, we identify it as quickly as we can, and ship it to wherever it is needed most so that everyone wins."

Are the boosters the same composition and volume as previous doses?

The Ministry of Health says the answer to this question is yes.

However, Conwaysays it's possible a booster of Modernacould be a half dose, and Pfizer a full dose.

"That relates to the fact that there's much more antigen, much more of a dose of the viral RNA present in the Moderna compared toPfizer," he said.

Will we needto get more booster shots in future?

The answer to this question is still uncertain, but Conway said he wouldn't be surprised if an annual immunization against COVID-19 is needed, or if it was included in the annual flu shot.

"It's possible, if not likely, that we will be getting a yearly COVID shot," said Conway.

"I think it's useful for us to start thinking of COVID as endemic, much like the flu is. The future, for me, is that there will always be COVID around, but we will be able to deal with it more productively in a new normal that will be comfortable for us."

Will we be notified automatically about our 3rd dose?

If you registered online for your first or second shot, you will automatically receive an invitationwhen it is your time to get a booster.

All eligible people in B.C. will be offered a booster shot, and once you become eligible, you remain eligible you will not miss your opportunity to get your booster dose.

Will pregnant people get a 3rd dose before January?

Booster shots for people who are pregnant will follow the same timelines as those in their age and risk group.

Why has information around COVID-19 and vaccines changed over time?

Because the coronavirus is a new and changing virus, information released today could be revised in the future as more data and research becomes available, said Conway,as has happened since the advent of the pandemic.

"We're sort of paving the runway as the plane is in approach," he said.

"If what I say today changes in two weeks, it isn't because today's statement is incorrect, it's because new science came to light."