Underlying Medical Conditions

People with underlying health conditions who are at risk for severe outcomes from COVID-19 include:

  • Solid organ transplant recipients,
  • individuals with specific cancers
    • who are undergoing active chemotherapy
    • people with lung cancer who are undergoing radical radiotherapy
    • people with cancers of the blood or bone marrow such as leukemia, lymphoma or myeloma who are at any stage of treatment
    • people having immunotherapy or other continuing antibody treatments for cancer
    • people having other targeted cancer treatments that can affect the immune system, such as protein kinase inhibitors or PARP inhibitors
    • people who have had bone marrow or stem cell transplants in the last six months or who are still taking immunosuppression drugs,
  • people with severe respiratory conditions, including all cystic fibrosis, severe asthma and severe chronic obstructive pulmonary disease (COPD)
  • people with rare diseases that significantly increase the risk of infections (such as severe combined immunodeficiency (SCID), homozygous sickle cell disease)
  • people on immunosuppression therapies sufficient to significantly increase risk of infection (biologic modifiers, high dose steroids, AZT, cyclophosphamide)
  • people who had their spleen removed
  • adults with very significant developmental disabilities (such as Down’s Syndrome) that increase risk
  • adults on dialysis or with chronic kidney disease (stage 5)
  • women who are pregnant with significant heart disease, congenital or acquired,
  • significant neuromuscular conditions requiring respiratory support

Who is considered immune compromised?

Examples of immunocompromised or immunosuppressed individuals include

  • receipt of treatment for solid tumors and hematologic malignancies (including individuals with lymphoid malignancies who are being monitored without active treatment),
  • receipt of solid-organ transplant and taking immunosuppressive therapy,
  • receipt of chimeric antigen receptor (CAR)-T-cell or hematopoietic stem cell transplant (within 2 years of transplantation or taking immunosuppression therapy),
  • moderate or severe primary immunodeficiency (e.g., DiGeorge syndrome, Wiskott-Aldrich syndrome, common variable immunodeficiency, Good’s syndrome, hyper IgE syndrome),
  • advanced or untreated HIV infection, and/or
  • active treatment with high-dose corticosteroids (i.e., ≥20 mg prednisone or equivalent per day when administered for ≥2 weeks), alkylating agents, antimetabolites, transplant-related immunosuppressive drugs, cancer chemotherapeutic agents classified as severely immunosuppressive, tumor-necrosis factor (TNF) blockers, and other biologic agents that are immunosuppressive or immunomodulatory.

How many doses are recommended for individuals who are moderately to severely immunocompromised?

The National Advisory Committee on Immunization (NACI) has recommended an additional dose of the COVID-19 vaccine for those who are moderately or severely immunocompromised  in order to provide additional protection against the virus.

Those who are moderately to severely immunocompromised will need three doses of vaccine to complete their primary series:

  • active treatment for solid tumour or hematologic malignancies
  • receipt of solid-organ transplant and taking immunosuppressive therapy
  • receipt of chimeric antigen receptor (CAR)-T-cell therapy or hematopoietic stem cell transplant (within 2 years of transplantation or taking immunosuppression therapy)
  • moderate to severe primary immunodeficiency (e.g., DiGeorge syndrome, Wiskott-Aldrich syndrome)
  • Stage 3 or advanced untreated HIV infection and those with acquired immunodeficiency syndrome
  • active treatment with the following categories of immunosuppressive therapies: anti-B cell therapies (monoclonal antibodies targeting CD19, CD20 and CD22), high-dose systemic corticosteroids (e.g. 20 mg/day for ≥ 14 days), alkylating agents, antimetabolites, or tumor-necrosis factor (TNF) inhibitors and other biologic agents that are significantly immunosuppressive.
  • Dialysis patients

5 1/2 months after the completion of the primary series (3 doses), a booster dose of an mRNA COVID-19 vaccine (Pfizer Comirnaty® or Moderna Spikevax®) is strongly recommended.

A 2nd booster dose is recommended 4- 6 months after the 1st booster dose has been administered.

Published date: 
May 3, 2022