In People With Cancer, COVID-19 Vaccine Boosters Reduce Hospitalizations

Image credit: Mufid Majnun

In a large study published today, both COVID-19 monovalent and bivalent boosters demonstrated a reduction in hospitalizations for the virus among people with cancer who received chemotherapy or immunotherapy within the previous year. ¹

The study looked at both the monovalent booster period (January-August 2022) and bivalent booster period (September-August 2023), when the booster vaccination was formulated to combat multiple strains of COVID-19. The study’s findings were published in JAMA Oncology. ¹

In a study of over 72,000 cancer patients, those receiving a monovalent COVID-19 booster saw a reduction of hospitalization rates compared to those who received only the primary vaccine series. “The COVID-19 hospitalization rate was 30.5 per 1000 person-years among patients who received a monovalent booster vs 41.9 per 1000 person-years among patients who received the primary series alone, with an adjusted VE of 29.2% (95%CI, 19.9%-37.3%) and NNV [number needed to vaccinate] to prevent 1 COVID-19 hospitalization of 166 (95%CI, 130-244),” the investigators wrote. ¹

In the bivalent booster period, there was also a reduction of hospitalization rates realized in a larger cohort study with over 88,000 patients with cancer.

"Patients who received this booster (38%) had a COVID-19 hospitalization rate of 13.4 per 1000 person-years vs 21.7 per 1000 person-years among persons who did not receive a bivalent vaccine, with an adjusted VE of 29.9% (95%CI, 19.4%-39.1%) and NNV to prevent 1 COVID-19 hospitalization of 451 (95%CI, 345-697),” they reported. ¹

Booster Differences

The boosters had similar reductions in COVID-19 hospitalizations— monovalent (29%) and bivalent (30%)—but the NNV saw differences. Whereas, the monovalent group had a number needed to vaccinate of 166, the bivalent group had a NNV of 451. ¹

Uptake for the boosters was low, especially for the bivalent with only 38% receiving it. For the monovalent booster, uptake was significantly higher with 69% receiving it. Still this number is less than optimal, according to the investigators.¹

COVID-19 And Cancer

It has been reported that people with cancer are at an increased risk for severe COVID-19 including hospitalization and mortality. As with most claims, there is some nuance to these findings.

Henley et al found the number of cancer deaths that were due to noncancer underlying conditions such as COVID-19 was highest during winter months in 2021 and 2022, which corresponded to peaks in COVID-19 infection.²

They also pointed out that while many cancer deaths had COVID-19 as an underlying cause, deaths may have had other factors involved. “Other cancer deaths during this time might have had underlying conditions (eg, heart disease) exacerbated by unreported COVID-19 illness or underlying conditions (eg, drug overdose or cirrhosis) exacerbated by changes in health behaviors during the pandemic,” the authors wrote.²

Additionally, the types of cancer also saw differing mortality rates.

“A higher percentage of hematologic cancer deaths had COVID-19 as the underlying cause (7.4% of leukemia, 7.3% of non-Hodgkin lymphoma, and 5.8% of myeloma deaths) compared with 0.6% of pancreatic cancer deaths, 2.8% of breast cancer deaths, and 3.6% of prostate cancer deaths,” Henley and coinvestigators wrote.²

Study Parameters, Final Takeaways

Investigators conducted a retrospective cohort study using data from 4 healthcare systems examining booster patterns in patients with cancer. In the earlier cohort, looking at the monovalent booster, the study included 72 831 persons with cancer (17 922 female individuals [24.6%]). In the other cohort, 88 417 persons with cancer (24 589 female individuals [27.8%]).

In terms of the study’s overall findings, the investigators found favorable benefit to boosters for this patient population. “COVID-19 booster vaccinations were associated with significant protection against severe COVID-19, with a favorable NNV among persons with cancer,” they wrote.¹

References
1. Skarbinski J, et al. COVID-19 Vaccine Booster Uptake and Effectiveness Among US Adults With Cancer. JAMA Oncol. doi:10.1001/jamaoncol.2025.2020
Published online July 17, 2025.
2. Henley SJ, Dowling NF, Ahmad FB, Ellington TD, Wu M, Richardson LC. COVID-19 and Other Underlying Causes of Cancer Deaths - United States, January 2018-July 2022. MMWR Morb Mortal Wkly Rep. 2022 Dec 16;71(50):1583-1588. doi: 10.15585/mmwr.mm7150a3. PMID: 36520660; PMCID: PMC9762902.