More at-risk Canadians can now get a third booster shot of a Pfizer or Moderna COVID-19 vaccine. 

The new guidance from the National Advisory Committee on Immunization, released Friday, makes the shot available to moderately or severely immunocompromised people. 

The agency says it continues to examine the need for booster doses, which, unlike additional doses, are intended to restore the levels of protection seen shortly after the first and second shots.