Letter to Public Health Officials and Agencies on



COVID-19 has unprecedentedly disrupted the Canadian healthcare system, affecting the millions of Canadians requiring care and treatment. We commend the provinces and territories in their efforts in integrating cancer patients into their respective immunization plans. We continue to encourage rapid access to immunization phases prioritizing cancer patients and immunocompromised survivors so those most at risk do not experience further delays in receiving the COVID-19 vaccine.

Nearly one in two Canadians will be diagnosed with cancer in their lifetime, with over 2 million Canadian cancer patients and/or survivors1. This number is rising with the aging population. The impact of cancer on Canadians has improved over the last few decades, with Canadians facing a cancer diagnosis now having a better chance of surviving than ever before. However, COVID-19 has severely impacted this statistic, causing increased severity and risk of mortality for cancer patients and survivors who contract SARS-CoV-2. This risk is further exacerbated in immunocompromised patients, especially those not eligible for the COVID-19 vaccine due to immunosuppressive treatments, that are living in households with caregivers or relatives who have not yet received the COVID-19 vaccine. The Manitoba government has taken this important consideration into account, factoring household members of high-risk individuals into their immunization plan to increase the patient’s protective environment2.

We further commend the National Advisory Committee on Immunization (NACI) for its continued monitoring and evaluation of vaccine research and development as well as real-world evidence, in this rapidly evolving environment. The continuous publishing and updating of the recommendations for vaccine roll-out is extremely important. NACIs response to extending dose intervals to four months to optimize early vaccine rollout has created much concern in the oncology community. Research on the efficacy of the COVID-19 vaccine with a four-month interval between doses is unavailable and therefore cannot be supported. Further NACIs most recent recommendations (March 16, 2021) do not explicitly address cancer patients and survivors nor takes into account the heterogeneity of cancers3,4.

Research into the COVID-19 vaccines and cancers is expanding, with recent studies demonstrating the immune response that occurs after the first dose of the vaccine in seniors5 and cancer patients6 is reduced compared to the response in healthy individuals, leaving these individuals unprotected. Immune protection in cancer patients at week 3 following the first dose of the vaccine was only 39% and 13% in solid and hematological cancers respectively, compared to 97% in those without cancer (research specific to the Pfizer-BioNTech vaccine)6. When the second dose was given at the proper 3-week time period, immune response increased significantly to 95%5. However, for those that did not receive the vaccine at a 5-week assessment period post-initial dose, only 43% and 8% of solid tumor and blood cancer patients developed antibodies, compared to 100% of controls6. In recognition of these data, as of March 26, 2021, the Ontario government has revised its second vaccine dose timeline for some immunocompromised patients including recipients of solid organ transplants; recipients of hematopoietic stem cell transplants; people with malignant hematological conditions undergoing active treatment; and people with non-hematological malignant solid tumours undergoing active treatment, where active treatment includes chemotherapy, targeted therapies, immunotherapy, and excluding individuals receiving solely hormonal therapy or radiation therapy7. We welcome this revision as a step in the right direction for cancer patients.

Recommendation 1:

We are urging that the provincial and territorial ministries ensure that all blood cancer patients, cancer patients on active treatment, and immunocompromised survivors receive the second vaccine dose according to the time supported by the product monograph indicated by clinical trial data to ensure proper immune response.

*dosing schedule can be individualized based on your clinician’s advice.

Recommendation 2:

We encourage the prioritization of all household caregivers or relatives of hematologic patients receiving immunosuppressive treatments to receive the COVID-19 vaccine. This will increase the protective environment for the patient against COVID-19 who may not be eligible to receive the vaccine due to treatment.

Recommendation 3:

We are asking to ensure a more rapid development of national guidelines and recommendations to include information for immunocompromised patients, including cancer patients specific to cancer type and treatments, on the safety and efficacy of the vaccine based on new and available research.

These recommendations were developed by the Lymphoma Canada Scientific Advisory Board and supported by clinicians affiliated with other patient organizations including CLL Canada, Canadian Myeloma Research Group via Myeloma Canada, Leukemia and Lymphoma Society of Canada and Lung Cancer Canada, along with one clinician not affiliated with a patient group. On April 2nd, 2021, these recommendations were sent to public health officials and agencies including provincial and territorial health ministers, chief medical officers, premiers, cancer agencies, Health Canada and NACI. We are urging health officials to consider recent evidence that supports timely administration of the COVID-19 vaccine doses, prioritization of household members of patients ineligible to receive the vaccine, and increased guidance for cancer patients, to provide optimal healthcare management for lymphoma patients across Canada.

For more information about your province’s/territory’s immunization plan, please visit https://www.lymphoma.ca/covid-19-information-hub/.


  1. Public Health Agency of Canada. Cancer in Canada. 2018. Available at https://www.canada.ca/content/dam/phac-aspc/documents/services/publications/diseases-conditions/fact-sheet-cancer-canada/fact-sheet-cancer-canada.pdf (accessed March 18, 2021)
  2. Government of Manitoba. COVID-19 vaccine current eligibility criteria. Manitoba, March 29, 2021. Available at https://www.gov.mb.ca/covid19/vaccine/eligibility-criteria.html (accessed on March 30, 2021)
  3. Government of Canada. NACI rapid response: Extended dose intervals for COVID-19 vaccines to optimize early vaccine rollout and population protection in Canada. 2021-03-08. Article can be found at: https://www.canada.ca/en/public-health/services/immunization/national-advisory-committee-on-immunization-naci/rapid-response-extended-dose-intervals-covid-19-vaccines-early-rollout-population-protection.html
  4. Government of Canada. Recommendations on the use of COVID-19 vaccines. 2021-03-16. Article available at: https://www.canada.ca/en/public-health/services/immunization/national-advisory-committee-on-immunization-naci/recommendations-use-covid-19-vaccines.html
  5. Brockman, M.A. et al. (2021). Weak humoral immune reactivity among residents of long-term care facilities following one dose of the BNT162b2 mRNA COVID-19 vaccine. MedRxiv. Available at https://www.medrxiv.org/content/10.1101/2021.03.17.21253773v1
  6. Monin-Aldama, L. et al. (2021). Interim results of the safety and immune-efficacy of I versus 2 doses of COVID-19 vaccine BNT162b2 for cancer patients in the context of the UK vaccine priority guidelines. MedRxiv. Available at: https://www.medrxiv.org/content/10.1101/2021.03.17.21253131v1
  7. Ontario Ministry of Health. Vaccine clinical advisory group (VCAG) recommendations on exceptions to extended dose intervals for COVID-19 vaccines. Mar 26, 2021. Available at https://www.scribd.com/document/500833873/Vaccine-Clinical-Advisory-Group-Recommendation-on-Extended-Doses (accessed Mar 29, 2021).