Blood Cancer Patients Report Lower Immune Response From mRNA Vaccine
Two new studies published in the journal Blood on April 15, 2021, suggest mRNA COVID-19 vaccines may have reduced efficacy in individuals with chronic lymphocytic leukemia (CLL) and multiple myeloma (MM), two types of blood cancer.
Interestingly, the research revealed wide variations in immune response among patients with CLL depending on where they were in their cancer treatment process.
The first study reports that people with CLL had markedly lower immune response rates to the two-dose of the Pfizer-BioNTech COVID-19 Vaccine (Comirnaty) than healthy individuals of the same age. Because clinical trials of these vaccines did not include patients with blood cancers who are at high risk of severe illness and complications from the virus, gauging the vaccine's effectiveness in this population is critically important.
In this study of 167 patients with CLL, only four out of 10 (39.5%) had a positive antibody-mediated response to the mRNA vaccine.
The second blood cancer study reported similar findings after the first dose of the same mRNA vaccine in elderly patients with multiple myeloma.
Evangelos Terpos, M.D., Ph.D., of the National and Kapodistrian University of Athens in Athens, Greece, and colleagues compared outcomes of 48 patients with multiple myeloma and 104 healthy controls at Alexandra Hospital in Athens. The median age of all participants was 83.
On day #22, after the first dose of the vaccine but before the second dose, antibody titers were measured. The median response was 20.6%, neutralizing antibodies for the MM population compared to 32.5% for the healthy controls.
They also wrote that administering a second timely vaccine dose is essential for elderly patients with multiple myeloma to develop an adequate antibody-based response.
These researchers note that the same trends would be expected with other mRNA vaccines, such as the vaccine produced by Moderna, Inc.
For more information about COVID-19 vaccines for immunocompromised people, see the American Society of Hematology's FAQs, last updated on April 5, 2021.