Canada’s National Advisory Committee on Immunization (NACI) recommends booster shots of COVID-19 for all adults 80 years of age and older, and also opens the door for certain other groups who may be at increased risk of decreased blood loss. protection over time from their first vaccination.
“Populations at the highest risk of declining protection after their primary series and at highest risk of severe COVID-19 disease should be offered a booster dose of a COVID-19 mRNA vaccine at least six months after completing their primary series ” The new NACI guidance released on Friday said: noting that people aged 80 and over “should” be offered a booster shot.
The NACI also said other people “may” be offered a booster because they “may be at increased risk of decreased protection over time since vaccination, increased risk of serious illness or who are essential. maintaining the capacity of the health system “.
Although NACI makes recommendations, it is up to the provinces and territories to decide who they will offer booster shots to.
These groups include:
- Adults between 70 and 79 years old.
- Anyone who has received two doses of AstraZeneca / COVISHIELD vaccine or one dose of Johnson & Johnson / Janssen (J&J) vaccine.
- Adults in or from First Nations, Inuit and Métis communities.
- Adults who are front-line health workers who have direct face-to-face contact with patients and who have been vaccinated with a very short interval between their first and second dose (three or four weeks).
The booster shots should be given at least six months after the second dose of the vaccine, the NACI said. The boosters are also expected to be one of the mRNA vaccines – Pfizer-BioNTech or Moderna, he said.
In alberta, Aboriginal people 65 years of age and over, and others 75 years of age and over may already receive booster shots.
On Thursday, the Northwest Territories announced that anyone 18 years of age or older will now be eligible for a booster shot.
Last week, British Columbia said people aged 70 and over, all Indigenous people aged 12 and over, and healthcare workers who had only three or four weeks between their two doses will all be able to receive a recall by the end of the year. . By next May, everyone in British Columbia will be eligible for one.
After the release of the NACI guidelines on Friday, the Ontario government announced that it will release its plan for COVID-19 boosters next week.
Why would people who received two doses of AstraZeneca need boosters?
Those who have received viral vector vaccines – two doses of AstraZeneca (licensed in Canada) or one dose of J&J vaccine (a single-dose vaccine licensed in the United States) – are on the list for a booster because the evidence have been shown to have “a little less initial vaccine effectiveness” and people who have received these vaccines “may become susceptible to infection earlier than people who have received a primary series consisting of at least one dose of ‘an mRNA vaccine,’ NACI said.
What is the difference between a booster and a 3rd dose?
The three COVID-19 vaccines approved in Canada (Pfizer-BioNTech, Moderna and AstraZeneca) are all two-dose regimens. A third dose is for people who may not have developed an immune response strong enough to fight COVID-19 after two doses.
NACI has recommended third doses for older people living in long-term care facilities and those with special health conditions who make them immunocompromised. For these people, a third dose is an extension of their primary series of vaccinations.
A booster is intended for people who have likely had a complete immune response to the regular two-dose vaccination schedule, but “over time, immunity and clinical protection have fallen below a level considered sufficient in this population”, according to the World Health Organization (WHO).
This is comparable to the tetanus vaccine, which requires a booster every 10 years. Most experts agree that everyone is likely to need a COVID-19 booster at some point over the next year, but the big question is when.
Long-term care home residents, immunocompromised already prioritized
NACI had previously recommended third doses for people living in long-term care homes or other gathering places, as well as for people with specific immunocompromised disorders.
In its guidelines on Friday, the advisory group said it continued to “strongly recommend” that people with moderate to severely immunocompromised people receive a third dose of the vaccine. People in this category include:
Those in active treatment for solid tumors or cancers of the blood.
Organ transplant recipients undergoing immunosuppressive therapy.
People receiving chimeric antigen receptor (CAR) -T therapy or hematopoietic stem cell transplantation (within two years of transplantation or following immunosuppressive therapy).
People with moderate to severe primary immunodeficiency (eg, DiGeorge syndrome, Wiskott-Aldrich syndrome).
People with untreated stage 3 or advanced HIV infection and those with AIDS.
People receiving active treatment with certain immunosuppressive therapies.
Why isn’t Canada just giving everyone boosters?
At a press conference on Friday, Dr. Theresa Tam, Canada’s chief public health officer, said it was “possible” there was a national recommendation for everyone to get reminders COVID-19 at one time, but not now.
At this point, “a primary series of vaccines [still] offers good protection to the general public, ”Tam said, adding that the boosters could be rolled out on a“ phased approach ”over time – just like the initial vaccinations.
Dr Christopher Labos, cardiologist and epidemiologist in Montreal, agreed.
“The majority of the population doesn’t need a booster right now, but… it’s reasonable to do in some high-risk groups,” Labs told CBC News Network on Friday after the announcement.
Another big reason, according to many health experts, is “vaccine fairness”. Much of the world, especially Africa, has not even received a first dose yet, according to the WHO.
The WHO has repeatedly urged rich countries to stop giving what it considers unnecessary reminders to people already protected from COVID-19 so that these vaccines can be rerouted to developing countries.
“We plan to distribute additional life jackets to people who already have life jackets, while we let other people drown without a single life jacket,” he added. Dr Mike Ryan, Head of the World Health Organization, said at a press conference in August.
Many infectious disease and immunology experts agree that in addition to ethical considerations, it is in Canada’s best interest to help ensure that people in developing countries receive the COVID-19 vaccines they need.
This is because the longer the coronavirus that causes COVID-19 can circulate among unvaccinated people, the more likely it is to mutate into new variants that put everyone at increased risk.
“These vaccines are valuable,” said Dawn Bowdish, Canada Research Chair in Aging and Immunity and professor at McMaster University in Hamilton, in a previous interview with CBC News. “If we want to make sure there isn’t the next variant and the variant after this and the variant after that, we really have to get the world vaccinated.”
I keep hearing people talk about “declining immunity”. Does this mean I need a reminder?
The term “waning immunity” generally refers to a decrease in antibodies over time. After any vaccination, immunologists and virologists say: it is normal for antibody levels to drop.
But the immune system is more than antibodies. B cells and T cells are also hard at work. B cells produce antibodies and if they are exposed to the virus again, they “remember” and can make more. T cells target and kill infected cells.
A study published in the journal Science found “robust cellular immune memory” of B cells for at least six months after mRNA vaccination against all circulating strains of the virus – even the highly contagious delta variant.
Many experts agree that lowering antibodies does not automatically translate into the need for a booster.