Gloved hand holding COVID-19 vaccine in syringe on a background of SARS-CoV-2 particles
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Blood cancer patients have a much more protective antibody response after COVID-19 booster shots, new research from Brown University shows. The study, in Cancer this week, found that less than half of patients with hematologic malignancies mounted detectable antibodies after initial COVID-19 vaccination, but 56% of the non-responders produced antibodies after receiving a booster dose.

“Our findings build on the wealth of literature showing that patients with hematologic malignancies have an impaired response to COVID vaccination. Importantly, we show that many of these patients who did not respond initially will in fact have a response to booster vaccination,” Thomas Ollila, MD, of Brown University, and the study’s lead author, told Inside Precision Medicine.

The immune response of people with hematologic malignancies, including leukemia, lymphoma, and multiple myeloma, affected by both their disease and its treatment, putting them at risk of severe COVID-19 infection and having a reduced response to COVID-19 vaccination.

“Blood cancers, even without treatment, decrease the body’s ability to have an immune response because abnormal lymphocytes cannot function properly to recognize the antigen created by the vaccine,” Ollila said.

Analyzing Antibody Responses

For the study, the team retrospectively analyzed antibody responses to initial and booster COVID-19 vaccination in 378 patients with hematologic malignancies.

Anti-SARS-CoV-2 antibodies were detected in the blood of 181 patients (48%) after initial vaccination with one of three US Food and Drug Administration (FDA)-authorized or approved COVID-19 vaccines, and patients with active cancer or those recently treated with an immune cell–depleting therapy were least likely to produce these antibodies. Among patients who did not mount an antibody response following initial vaccination, responses were observed after a booster dose in 48 of 85 (56%) patients who were assessed.

By the end of February 2022, 33 patients (8.8%) developed a COVID-19 infection, with three COVID-19-related deaths (0.8%). Although there was no significant link between post-vaccination antibody response and incidence of COVID-19 infection, no patient with antibody responses died from COVID-19.

The authors wrote: “Booster vaccinations can promote seroconversion in a significant proportion of patients who are seronegative after the initial vaccination course regardless of the specific vaccine or on/off treatment status at the time of revaccination.”

Benefit of Antibody Therapy

Also, no patient who received antibody therapy with tixagevimab plus cilgavimab was diagnosed with a COVID-19 infection. These antibodies bind to non-overlapping portions of the SARS-CoV-2 spike protein, preventing the virus from binding to and infecting cells. The FDA authorized the combination therapy for emergency use during the COVID-19 pandemic as a way to help prevent COVID-19 infection in certain individuals.

Ollila noted that, “When we looked at outcomes, we found that deaths from COVID-19 in the patient population we reviewed only occurred in those with undetectable antibodies, and nobody who received prophylactic antibody therapy was diagnosed with COVID-19. This suggests to us the importance of checking antibody levels in these patients and arranging prophylactic antibody therapy.”

Ollila said the diverse response among these patients to vaccines is still not clear, but may be due to a variety of factors: “Timing from treatment, degree of depletion of lymphocytes all play a part. The degree of immunodeficiency can also vary from person to person with the same disease.”

He encourages providing booster vaccines for patients and prioritizing prophylactic antibody therapy when indicated. “This is real world evidence that these actions can save lives,” he said.

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