There are 2 such vaccines now in use in the United States; the Pfizer-BioNTech vaccine is fully approved for the first 2 doses for those 16 and older, and the Moderna vaccine has an emergency use authorization for those 18 and older.
A year after FDA allowed distribution of the first COVID-19 vaccines, and a month after booster shots were authorized for Americans over age 18, a registry study has found that third shot of mRNA vaccine could be crucial for some patients with blood cancers.
Data presented this week by the Leukemia and the Lymphoma Society (LLS) at the 2021 American Society of Hematology Annual Meeting and Exposition show that 43% of patients with blood cancers will produce antibodies after receiving the third dose of mRNA vaccine. This is the “booster” shot that for most patients comes 6 months after the initial 2 doses, which are given 3 or 4 weeks apart, depending on the vaccine.
Some patients who received their third dose reached antibody levels on par with healthy adults, confirmed by measuring levels of detectable antibodies to the spike protein in SARS-CoV-2 before and after the third dose of the mRNA COVID-19 vaccines. As of December 13, 2021, there were 2 such vaccines in use in the United States; the Pfizer-BioNTech vaccine is fully approved for adults for the first 2 doses for those 16 and older and authorized for those age 5 to 15, while the Moderna vaccine has an emergency use authorization for those 18 and older.
Results from study based on the Leukemia and Lymphoma Society Registry demonstrate that patients with blood cancers who had at least some antibodies after the first 2 doses are likely to produce large amounts after they receive their booster doses.
"Our data shows a clear benefit of giving blood cancer patients three primary vaccine doses, but there is still a large portion of patients who will remain at risk even with the additional dose," Lee Greenberger, PhD, LLS chief scientific officer, said in a statement.
In this study, about 20% (139/699) of blood cancer patients still had no measurable COVID-19 antibodies after the third dose. The results, reported December 11, 2021, are from the largest pool of patients with blood cancer patients reported thus far.
As of July 2021, the LLS registry includes 24 patients who received a third vaccine dose after receiving the first 2 doses with mRNA vaccines. Of these 24 patients, 20 were seronegative more than 14 days after their second shot, as measured by the Roche Elecsys assay; 4 patients had low positive serology results. All patients were nucleocapsid antibody negative.
These patients ranged in age from 51 to 79 years; 11 had chronic lymphocytic leukemia (CLL), 7 non-Hodgkin’s lymphoma (NHL), 5 Waldenstrom’s macroglobulinemia (WM), and 1 multiple myeloma (MM). As for therapy, 6 patients were not currently receiving anti-B-cell therapy, 11 had received anti-CD20 therapy, including 8 within the prior 6 months; 6 had received Bruton tyrosine kinase inhibitors within the last 6 months, and 1 patient had received recent chemotherapy.
Booster shots were received between April and June 2021, 21 to 114 days after patients received the second of their first 2 shots between January and April 2021; clinical guidelines called for patients with cancer to be first in line to receive COVID-19 vaccines.
The abstract offered details of each patient’s type of therapy and response to the vaccine. “In this limited set of patients, there was no evident pattern of antibody response amongst patients who received homologous versus heterologous vaccine nor between disease types,” the authors wrote. “While anti-CD20 therapy appeared to reduce antibody response to booster vaccination, there was substantial heterogeneity.”
They noted that although patients with B-cell malignancies did not mount a robust response to first 2 mRNA vaccines, several patients demonstrated an antibody response to the booster. The authors called for clinical trials to understand which patients may benefit from a booster strategy, whether prior therapy affects response to vaccines, and how to offer these shots safely.
Greenberger LM, Saltzman LA, Senefield JW, Johnson PW, DeGennaro LJ, Nichols GL. SARS-CoV-2 antibody levels in blood cancer patients after a third SARS-CoV-2 “booster” vaccination—observational data from the LLS national registry. Abstract 185.