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Statement on Recent mRNA-based COVID-19 Vaccines Studies for Blood Cancer Patients

The Leukemia & Lymphoma Society (LLS) has heard from blood cancer patients and caregivers who are concerned about new research suggesting that mRNA-based COVID-19 vaccines may offer less protection for people with certain blood cancers.

The findings from the new research confirm what LLS and other experts expected: that certain types of blood cancer and blood cancer treatments could affect vaccine response. Additional research is underway including collection of real-world data in the LLS National Patient Registry, created in honor of Michael Garil to provide more data to help patients and their healthcare providers make informed vaccination decisions.

LLS continues to recommend that all blood cancer patients and survivors talk to their healthcare team as soon as possible to make a plan for vaccination. People with blood cancers are at higher risk of serious outcomes from COVID, including death, so any vaccine protection is better than none. Data from these studies and from the LLS National Patient Registry show no significant differences in reported vaccine side effects among blood cancer patients compared to those who never had cancer. It is also important to continue following recommended CDC precautions including wearing a mask, avoiding crowds, keeping a social distance and encouraging vaccination among household and other close contacts.

More about the current studies

In the first study, four out of ten patients with chronic lymphocytic leukemia (CLL) who received two doses of the Pfizer-BioNTech vaccine showed a positive immune response, compared with nearly 100% of healthy, similarly aged people. This research revealed differences in immune response depending on where patients were in their CLL treatment. Patients undergoing active treatment had the lowest response rate (16%) while those who had completed treatment and were in remission had the highest (79%). Patients still in the “watch and wait” category had a 55.5% response rate, which demonstrates that CLL itself has an impact on immune response. This study included 167 patients with CLL and 53 healthy controls who received the Pfizer BioNTech COVID-19 vaccine.

In a second study, researchers reported similar findings after one dose of the Pfizer BioNTech vaccine in elderly patients (median age 83 years; range 59-92 years) with multiple myeloma (MM). Antibody responses were 20.6% for the MM population as compared to 32.5% for healthy participants of similar age and gender. While this study confirms a difference in vaccine response among patients with MM, it also demonstrates the importance of timely administration of the second vaccine dose as recommended to provide the best protection possible.

The findings from these two studies are consistent with an earlier report which indicated that the seroconversion rate three weeks after the first dose of the Pfizer-BioNTech vaccine in individuals with blood cancer, solid tumors, and health individuals was 17, 39, and 97%, respectively. Despite the low seroconversion rate, immunocompromised patients did demonstrate a T-cell response, albeit less than healthy individuals.

More about the LLS National Patient Registry

The LLS National Patient Registry, created in honor of Michael Garil is collecting data to provide more specific information about how people with blood cancer respond to the COVID-19 vaccines. Preliminary safety results from the Registry are encouraging and show that the side effect profile of the currently authorized vaccines appears to be very similar in blood cancer patients and survivors compared to the general public.