Vaccine boosters help keep cancer patients from being hospitalized or admitted to intensive care units due to COVID-19. This is the conclusion based on a study led by Cedars-Sinai investigators published on July 17, 2025 in JAMA Oncology.[1]
The study, supported by the National Cancer Institute Serological Sciences Network (SeroNet), the Physician Researcher Program of The Permanente Medical Group Delivery Science and Applied Research Program (JS), and the United States Veteran Administration, offers real-world evidence to support vaccine recommendations for these patients.
Jane Figueiredo, Ph.D., director of Community Health and Population Research at Cedars-Sinai. Photo courtesy: © 2025 Cedars-Sinai. Used with permission.A vulnerable population
“Cancer patients are a vulnerable population,” noted Jane Figueiredo, PhD, director of Community Health and Population Research at Cedars-Sinai and senior author of the study.
“Their immune systems can be weakened by their disease and the treatments they receive, which is why major health organizations recommend that these patients be vaccinated against COVID-19. Our study supports these recommendations. We used real-world data across four major health systems in the U.S. to show that these booster vaccines reduce the risk of hospitalization and severe illness.”
Investigators analyzed data on more than 161,000 patients treated for cancer during 2022 and 2023 at Cedars-Sinai, Kaiser Permanente Northern California, Northwell Health, and the Veterans Health Administration.
Reducing hospitalization
The data showed COVID-19 boosters reduced cancer patients’ hospitalizations and ICU admissions by 29% and prevented one hospitalization or ICU admission for every 150-166 boosted patients.
“The reduction in hospitalizations was significant, and the number of patients we needed to treat to see a benefit to the boosters is quite low,” explained Figueiredo, who is also program leader of Cancer Prevention and Control at Cedars-Sinai.
“This shows a great benefit to our cancer patients and should encourage patients to discuss vaccination with their healthcare providers,” she added.
Low participation
Figueiredo noted that among their sample, the percentage of patients receiving boosters was quite low. By January. 1, 2022, 68% had received a booster. And after updated boosters targeting more than one COVID-19 strain had become available, only 38% of patients had received one.
“Whether this is due to patient concerns about safety or provider uncertainty about whether to administer a vaccine during treatment is not clear,” Figueiredo said.
“What is clear is that we need to advocate strongly for vulnerable groups, including cancer patients, to receive these vaccines.”
Figueiredo noted that the COVID-19 pandemic was the first opportunity for investigators to examine data on mRNA vaccines, and five years later there is still much to learn about the effectiveness of these vaccines in various populations.
“This is the largest study to date of COVID-19 booster effectiveness in cancer patients, a high-risk population of critical importance,” said Robert Figlin, MD, interim director of Cedars-Sinai Cancer.
“It adds substantially to our understanding of the effectiveness of COVID-19 vaccines, and we will undertake additional studies as vaccine formulations change and new variants emerge so that we can make recommendations that best protect the health of our patients.”
Figueiredo’s team is preparing to publish vaccine effectiveness data on patients with autoimmune diseases and patients who have undergone solid organ transplants.
“There are several different groups whose immune systems have been affected in different ways, which gives us an opportunity to expand further our understanding of how these vaccines work,” Figueiredo concluded.
Reference
[1] Skarbinski J, Elkin EP, Ziemba YC, Kazemian E, Wilson BM, Siddiqui H, Schleicher CB, Hsiao CA, Nugent JR, Reckamp KL, Merchant A, Crawford JM, Zidar DA, Kushi LH, Figueiredo JC. COVID-19 Vaccine Booster Uptake and Effectiveness Among US Adults With Cancer. JAMA Oncol. 2025 Jul 17:e252020. doi: 10.1001/jamaoncol.2025.2020. Epub ahead of print. PMID: 40674059; PMCID: PMC12272354.
Featured image: 2018 – 2025 Fotolia.Adobe. Used with permission.
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