COVID-19 Vaccine Booster: Need?Experts participate

Barry-Some people are already planning booster shots as the move to vaccinate all eligible Canadians with COVID-19 continues.

On Friday, the National Advisory Board for Immunization (NACI) released the latest guidance on COVID-19 booster shots in Canada.

The Commission “highly recommends providing mRNA booster shots to people over the age of 50, the elderly living in long-term care facilities and other collective living facilities, and those who have received the complete series of viral vector COVID-19 vaccines. “. Johnson & Johnson and AstraZeneca.

NACI also strongly recommends providing booster shots to First Nations, Inuit, Metis people, and front-line healthcare professionals in direct contact with patients.

Authorities also recommend providing boosters to people between the ages of 18 and 49 at least 6 months after receiving the primary vaccine series.

But what is a booster shot, and does everyone ultimately need it? This is what the experts say.

What is a booster shot?

The COVID-19 booster shot is the third dose of the first vaccine, explained Dr. Matthew Miller, associate professor of biochemistry and biomedical sciences at McMaster University.

“For example, if you have been vaccinated twice with the mRNA vaccine, the booster shot will be the third vaccination of the same vaccine, the same dose and the same content,” he told CTV News.ca in early November.

Miller said it was similar to what you see in most traditional booster shots.

He said people would receive the same vaccine multiple times in order to “enhance the immune response evoked by the vaccine content.”

“Semantics are important,” said Dr. Isaac Bogoch, a member of the Department of Infectious Diseases at the University of Toronto, adding that the COVID-19 booster should actually be called a third dose.

Bogoch said many vaccines have been given three times, pointing to the hepatitis B vaccine as an example.

“So I think we should think of this as a three-dose vaccine series,” he told CTV News.ca in early November.

According to Bogoch, most people are “very likely” to need a third COVID-19 vaccine.

“Most of us have been vaccinated twice in a three-dose vaccine series,” he said.

Do I need a third dose?

Bogoch said there are several reasons why a third dose of the COVID-19 vaccine is needed.

He said that some people are not as responsive as others, namely the elderly and people with immunodeficiency.

Bogoch said he could “certainly benefit” from a third dose of the vaccine “earlier in the spectrum.”

According to Bogoch, another reason to give a third dose is to combat weakened immunity and defense. This can happen over time.

“Weakened protection actually refers to breakthrough infections,” he said. “Some studies overestimate the degree of it, but it’s still there, and it’s clear that a third dose will be needed to help people prevent it from happening.”

Bogoch said another reason for the need for a third dose was to further reduce the risk of serious outcomes and death, and to reduce the risk of infection in the first place.

Hello Studies from IsraelWe found that people over the age of 60 who received the third dose of the vaccine were 19.5 times less likely to develop severe COVID-19 than people of the same age who received only two doses. ..

“Therefore, it is no exaggeration to say that most people receive a third dose, because this must actually be a triple dose vaccine series,” he said.

Miller reiterated Bogoch’s remarks, saying that everyone thinks it is “unavoidable” that they will eventually need a third dose of the COVID-19 vaccine.

He added that NACI makes “evidence-based recommendations” in a way that “protects vulnerable populations” with those receiving a third dose.

How do researchers know if a different dose is needed?

When it comes to deciding whether additional vaccines are needed, researchers will consider a few different things, Miller said.

First, researchers study the effectiveness of the first vaccine series. They do this by monitoring their effectiveness in large populations, Miller explained.

“What we want to see is steady protection as it takes months from the completion of the primary vaccine series,” he said. “When we start seeing that decline, it’s really the most important signal that boosters may be needed.”

In addition to monitoring its effectiveness, Miller said some researchers have specifically examined the immune response produced by the vaccine.

“So they look at things like antibodies in people’s blood and cells (immune cells) in people’s blood and see what happens with those numbers,” he said. “This is a more incomplete measurement than looking directly at efficacy, but it can also show signs of potential need for boosters.”

Do Canadians need COVID-19 shots each year?

Both Miller and Bogoch said it was too early to know if Canadians needed the COVID-19 vaccine each year.

“It may be every year-maybe not, no one really knows,” Bogok said. “If someone speaks with high confidence about this, we really don’t know, so I think we should doubt.”

Miller said this “still needs a fairly thorough investigation.”

“On the other hand, it’s a decision that is influenced by how long immunity lasts,” he explained. “But it also has to do with how much the virus circulates. [and] How much has the virus evolved? “

Researchers are monitoring these things in real time every day to inform them of these decisions, Miller said.

Vaccines administered overseas

Canada will begin a third dose to people in need, but Miller says he should “still really think carefully” about other parts of the world where people haven’t even received the first jab. Said.

Making access to the COVID-19 vaccine “really useful for Canada,” Miller said, said that making people in other parts of the world accessible to the COVID-19 vaccine.

“The lower the infection rate internationally, the less likely it is that a problematic variant will emerge,” he explained.

Miller confirms that other countries have sufficient vaccines for their population and makes the third dose available to Canadians who need them “parallel.” It should be a “priority”.