The benefits of COVID-19 vaccination outweigh the unknown risks in haematopoietic stem cell transplant and CAR T-cell (TCT) patients.
According to the Australia and New Zealand Transplant and Cellular Therapies (ANZTCT) consensus position statement, there are currently no studies evaluating COVID-19 vaccines in TCT patients.
“Despite the lack of data, there is no immunologic rationale to suggest that these vaccines might be harmful, and there is no risk of developing COVID-19 from these vaccines as none are live vaccines.”
The statement also said other vaccine products have not been shown to worsen acute or chronic GVHD.
“Given the high mortality risk associated with COVID-19 in TCT patients, TCT patients and health care workers delivering care to these patients should be prioritised,” the statement said.
They also noted:
- The benefits of vaccination outweigh the unknowns in TCT patients without contraindications such as allergies to the vaccine.
- Patients planned for TCT should be vaccinated as soon as feasible prior to TCT without deferral of TCT.
- Optimal responses to the vaccine are more likely >6 months post TCT and when patients are off immunosuppressive therapy. Clinicians could consider vaccination as early as 3-6 months post TCT in patients aged >16 depending on local and community transmission and clinical factors.
- The unknown risks in the setting of GVHD are likely to be outweighed by the benefits, particularly in patients with lung GVHD. Therefore, in allogeneic HSCT recipients who remain on immunosuppressive therapy beyond 6 months, consideration should be given to the indication, intensity and expected duration of immunosuppressive therapy when deciding whether to vaccinate or defer. Especially if patients are close to weaning off immune suppressive therapy, a short period of deferral may improve immunogenicity to vaccination and would be appropriate in the context of well controlled community transmission.
- TCT patients should be advised to continue to practice usual public health measures (e.g. masks, physical distancing, avoiding crowds, ensuring good indoor ventilation, and hand hygiene) in accordance with national and regional guidelines after vaccination as immunogenicity and efficacy in these patients is unknown.
- Available vaccines are not licensed for use in patients under the age of 16 years noting that trials are underway to answer this question.
- Healthy bone marrow transplant donors should be vaccinated as soon as possible prior to donation, preferably within 3 months prior to donation without deferral of donation.
- Household transmission is one of the most common mechanisms of SARS-CoV-2 transmission so vaccination of household members and or carers of TCT patients should be prioritised.
- Acknowledging the lack of data for efficacy and safety in TCT patients, the Pfizer/BioNTech SARS-Cov-2 vaccine has high efficacy in the general population and is the only vaccine with (albeit limited) data in patients with haematological malignancy, and therefore considered the preferred vaccine in TCT patients, health care workers delivering their care and household members.
- Where possible, assessment of vaccine response with post vaccination serology testing should be performed in TCT patients.
- Studies to determine the optimal vaccine, timing, number of doses and schedule in TCT patients are urgently needed. It is also important to consider the role of donor vaccination and the role of vaccination in paediatric TCT patients since this cohort was excluded from the pivotal above mentioned studies.