4th dose of COVID-19 vaccine recommended for immunocompromised Manitobans

Manitoba is now offering a fourth dose of an mRNA COVID-19 vaccine to people deemed as moderately to severely immunocompromised.

Latest booster targeted at those moderately to severely immunocompromised

Immunocompromised Manitobans are eligible for a fourth booster shot after a period of at least six months has passed since the last dose. (Evan Mitsui/CBC)

Manitoba is now offering a fourth dose of an mRNA COVID-19 vaccine to people deemed as moderately to severely immunocompromised.

As with the third booster shot, the fourth should not be given until at least six months has passed since the last dose, the province posted on its website on Christmas Eve.

A complete list of the medical conditions and treatments that would result in a person being considered immunocompromised is available online.

Some examples include people who are receiving chemotherapy or immunotherapy for cancer; those who are on the list to receive a solid organ transplant or have received one and are currently receiving chemotherapy or other immunosuppressive therapy; those receiving hemodialysis or peritoneal dialysis, and anyone taking certain medications that severely affect the immune system.

Generally, the vaccine used for a fourth dose should be the same mRNA vaccine — Pfizer or Moderna — as the recipient's previous dose.

People are advised to talk to their doctor about which mRNA vaccine is right for them.

"Your doctor can advise you based on the emerging evidence and taking into consideration your immunization and medical history as well as personal circumstances," the province said in a post on its website..

The province has emphasized that a complete series of the same mRNA vaccine is preferable. However, a combination of those vaccines is still a better choice than a viral vector vaccine such as AstraZeneca or Janssen.

When it comes to people aged 12 to 29, though, the Manitoba government says it is now following the National Advisory Committee on Immunization's guidance that Pfizer be prioritized for first and second doses.

"This out of an abundance of caution because the risk of myocarditis/pericarditis — an extremely rare and temporary swelling of heart tissues — appears to be lower with Pfizer than it is with Moderna," the province's website states.

But if only Moderna is only available, or if someone in that age group chooses it over Pfizer, that is fine. 

"It's a very safe and effective option," the website noted, adding the risk of myocarditis/pericarditis is still much higher from a COVID-19 infection than it is from a vaccine.


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