Dr Navdeep Grewal, emergency room physician, practicing in Vancouver Coastal and Fraser Health Authorities, and Dr Birinder Narang, a family doctor working in East Vancouver and Burnaby, answer frequently asked questions about booster dose.
Why do I need a booster dose?
Booster doses of the Covid vaccine will boost your immunity, to prepare your antibodies fight the Covid virus when you are exposed to it.
Studies show waning immunity after the initial 2-dose series of vaccines, which means that protection against the virus and the ability to prevent infection with the new variants will decrease over time. This doesn’t mean the vaccines didn’t work or stopped working, it simply means that your body may not be fully prepared to fight off the virus and so you may experience a mild breakthrough illness from new variants.
But the good news is that you are still at very low risk of severe illness, hospitalization and death. With the booster dose, you are even better protected!
What is the difference between a primary series and a booster dose?
A primary series is the initial series of vaccinations that protect you against an illness. The number of doses required to complete a primary series is different depending on the vaccine, the microbe, or a person’s age or health.
A booster dose is given after the primary series to help you maintain and give you longer protection. This is routinely done for many vaccination series, eg tetanus, diphtheria, and now Covid.
What is the difference between a 3-dose primary series and a booster for Covid?
The 3-dose primary series is recommended and given to people with a compromised immune system (eg from chemotherapy, steroid therapy, or primary immunodeficiency diseases), because they generally have lower antibody response to a 2-dose covid vaccine series, so the 3rd dose completes their primary series.
This is different than a booster, which is given a few months after the primary series in people who are generally healthy and have likely mounted a full antibody response to the initial 2 doses.
When should I get a booster dose?
In BC, if you are age 18+, you will be invited to get your booster dose if it’s been at least 6 months since your 2nd dose of the primary series. The timing is based on your risk level of getting Covid infection, your age, whether you got AZ vaccines for your primary series, and the time since your 2nd dose. Many people are in these categories and have already been invited to receive their booster doses. We are expecting the booster program to ramp up significantly in the new year.
I got a mixed vaccine dose for my primary series. What will I get for my booster dose?
You will receive either Pfizer or Moderna for your booster dose, and either is fine. The key is to get an mRNA based booster.
Is Moderna booster dose given as a full dose or half dose?
A full dose of Moderna is given to longterm care residents, and those in assisted or independent living facilities, as well as to people aged 70 yrs+. This is done to fully boost their immune systems, which generally have a lower antibody response than those younger or not in care facilities.
All other eligible people will receive a half-dose for their booster dose.
Will I need a regular booster?
It’s possible that Covid vaccines will need just one boost, or maybe will need morein the future. We don’t know this yet, and it partly depends on formation of new variants and whether they manage to escape the immunity from our current vaccines.
But if we do require boosters, this will be no different than many other vaccination protocols, eg Tetanus, diphtheria, Hepatitis B, all of which require booster doses for longterm immunity.
How do I get my booster dose?
Everyone aged 18+ will be invited to get a booster dose at least 6 months after their second dose, and the timing will depend on your risk level for getting Covid, your age, and the time since 2nd dose.
If you were vaccinated before April 2021, you may not be registered on the government registry, even if you have your vaccine passport.To receive an invitation for your booster dosewhen you become eligible, you must be registered on the getvaccinated website.
