Earlier this week, B.C. announced it would be one of the first jurisdictions in North America to make a third COVID-19 booster dose available to the general public.
But just how critical a third dose will be in protecting someone from the virus depends on a number of factors, including age and pre-existing health problems.
Whereas in the past, vaccine recommendations have been largely consistent across the country, booster doses are leading different provinces and federal authorities to offer, at times, conflicting guidelines.
“It is a confusing time,” says Mark Brockman, a virologist at Simon Fraser University, who is part of a team studying long-term COVID-19 vaccine response in different populations.
Here’s what we know so far.
IS A THIRD DOSE MANDATORY?
No. In announcing the rollout of a third dose, Health Minister Adrian Dix said he encourages everyone who has had two doses to get a third. Anyone “who wants a booster shot will receive one,” he said.
WILL MY VACCINE CARD BE VALID IF I DON’T GET A BOOSTER?
As of Oct. 24, all British Columbians eligible for a COVID-19 vaccine must be double-dosed to enter everything from movie theatres, concerts and sporting events to gyms and restaurants.
A third dose will not be required to keep your vaccine card up to date.
WHEN CAN I GET A THIRD SHOT?
The B.C. government says people most at risk of getting COVID-19 will start being offered a third dose in November. By January 2022, a booster dose will start to be offered to everyone in B.C., approximately six to eight months after their second dose.
The first group includes anyone aged 70 and up and Indigenous people aged 12 and over. Health-care workers, as well as anyone living in independent living facilities or long-term care will also be offered a third shot before the general population.
Individuals living outside a congregate setting must be registered with the “Get Vaccinated” provincial system to receive a booking invitation. You will not be able to receive a third dose at a drop-in clinic.
WHY DO OLDER AND IMMUNO-COMPROMISED PEOPLE GET A THIRD DOSE FIRST?
Not every jurisdiction in Canada is moving to offer third doses for the general population.
So far, Canada’s National Advisory Committee on Immunization (NACI) — which has acted as a public health beacon for provinces over the past 10 months — has only recommended a third dose of an mRNA vaccine (Pfizer or Moderna) to people living in long-term care or seniors living in congregate settings.
Brockman says evidence shows these higher-risk groups need a third dose just to get them up to the normal protection seen in healthy people who received two doses.
SHOULD I MIX AND MATCH VACCINES?
When it comes time for a third dose, the province told Glacier Media British Columbians will be offered either the Moderna or Pfizer vaccine.
Pointing to NACI guidance, a spokesperson for the Ministry of Health said data shows people with a severe immediate allergic reaction after one dose of mRNA vaccine can receive a second dose of the same mRNA vaccine or another.
For people who received a mix of AstraZeneca and one of the mRNA vaccines for their first two doses, there will be “a small chance” they will get a different mRNA vaccine their third dose, wrote the spokesperson in an email.
“For the most part, all of those different vaccines are really just different technologies to show our immune system the spike protein from the virus,” says Brockman.
For that reason, he says, mixing any of the approved vaccines will be safe when it comes time to get a third jab.
Based on laboratory studies, a booster shot of anything is safe, boosting with an mRNA vaccine is probably better, and boosting with Moderna is probably the best of the two mRNA vaccines, says Brockman.
HOW LONG WILL A BOOSTER LAST?
Scientists and health officials are still collecting data on the length of protection a booster shot will provide individuals.
We should have some answers in the coming months as scientists like Brockman collect and analyze the effects third doses are having on different populations.
I’M HEALTHY AND DOUBLE-DOSED — DO I EVEN NEED A BOOSTER?
In announcing the rollout of third doses, provincial health officer Dr. Bonnie Henry said Tuesday the “highly effective” vaccines are showing a gradual decline in protection over time.
Studies, including from the BC Centre for Disease Control, have found that in a healthy person, vaccines usually provide protection from serious illness for at least six months.
But not every jurisdiction agrees, and NACI has not yet made any recommendations to provide a booster for the general population.
“Scientifically, we're learning about the vaccines kind of in real-time. So it depends on what observations people are making, in what settings in different places in the country,” says Brockman.
The discrepancies between groups like NACI and B.C.’s approach stem from Henry’s more proactive approach, says Brockman.
“For an otherwise healthy adult, there's probably as much if not more evidence that you don't need that third dose even six months later,” he says.
“People should get it if they feel, personally, it would provide them some peace of mind. But scientifically or clinically, they'll probably be just fine after two doses.”
IS A BOOSTER DOSE BEING GREEDY?
Brockman says there’s a good rationale to give elderly or immuno-compromised people a third dose to bring up their immunity. But for the rest of the otherwise healthy population, diverting vaccines for a third dose might do Canadians more harm than good.
The equity issues are profound, says Brockman. To start, offering people third doses of the vaccine in developed countries like Canada means taking from a global supply that could otherwise be used to give somebody a first or a second dose.
Brockman acknowledges that to not provide a third dose to healthy Canadians could be politically dangerous should the pandemic spiral out of control over the coming months. At the same time, he says it’s in Canada’s best interest to make sure the virus doesn’t spread in other countries.
“We’ll get more bang for our buck, from a global perspective, to give people who don't have the vaccine one or two doses than we will giving Canadians a third dose,” he says.
“In fact, it might be the only way that we're actually going to end the pandemic, because as long as the virus continues to circulate in places like India or South Africa, and variants pop up, we’re going to forever be looking over our shoulder to worry about the next thing that’s inevitably going to make its way into Canada.”
