This is a study of the response of cancer patients to vaccination. Some types of cancer can cause immunosuppression directly (by crowding out the immune cells needed to respond to the vaccine), and some types of cancer therapy can also cause immunosuppression.
As seen previously in immunocompromised people, there was a higher seroconversion rate with Moderna than with Pfizer, which was higher than J&J.
Seroconversion rates were higher with solid tumors than liquid ones (which makes sense, as blood cancers are the ones that can crowd out the immune system). Patients receiving anti-CD20 therapy (which destroys B-cells, which make antibodies) had lower rates of seroconversion. Bone marrow transplantation (which often comes with serious radiation or chemotherapy) also reduces rates of seroconversion.
Overall, the majority of cancer patients do make good levels of antibodies, but a significant minority have weak or no antibodies.
Link to study : https://www.medrxiv.org/content/10.1101/2021.05.07.21256824v1.full.pdf
