According to investigators at the University of Pennsylvania School of Medicine, a large percentage of blood cancer patients do not develop adequate antibodies to the COVID-19 vaccines. The study results were based on a small number (28) of blood cancer patients. 

It has been unclear how blood cancer patients will respond to the COVID vaccines. Will sufficient antibodies be developed? Blood cancer patients were not allowed to be included in the initial COVID-19 clinical trials. This lingering research question is an important one for AML patients as communities across the world open back up.

Blood cancer patients are at higher risk of COVID complications, with mortality rates exceeding 30%. Blood cancer patients can also develop prolonged shedding of infectious COVID-19, often lasting several months. It makes sense that blood cancer patients should be first in line for the vaccines. 

The investigators studied COVID-19 antibody responses in 28 blood cancer patients [chronic lymphocytic leukemia (CLL) (29.4%), lymphoma (31.3%), multiple myeloma (43%) and myeloid malignancies (5.97%)] seen at UPMC Hillman Cancer Center who had received two doses of either the Moderna or Pfizer vaccine. The median time between the two doses was 23 days. Patients who had previously had COVID-19 were excluded. 

Thirty patients (44.8%) were in active treatment and 37 (55.2%) were under observation or in remission.

Antibody tests were performed at the UPCM clinical laboratories using the Beckman Coulter SARTS-CoV-2 platform which detects IgG levels. 

In total, 31 patients (46%) had negative antibody results after vaccination and were considered to be vaccine non-responders. Older patients were more likely to be vaccine non-responders than younger patients. Other factors like IgG levels, number of days between vaccine doses, cancer therapy and antibody measurement did not differ between vaccine responders vs. non-responders. CLL patients were more likely to be non-responders, even when in remission. 

What does this mean for AML patients? It is still important to get the COVID-19 vaccine as there is greater than a 50% chance of it working for you (the CLL patient results increased the % of non-responders). With further study of just AML patients, it should become more clear. Asking your doctor for an antibody test to see if you have developed COVID-19 antibodies post-vaccine is a good idea. 

Until more data comes out specifically for AML patients, it is important to continue to wear masks and observe social distancing regardless of vaccination status.

Note: The original publication has not yet been peer-reviewed.