COVID-19 Vaccines Safe, Effective in Patients With Cancer

COVID-19 vaccination is both safe and effective for patients with cancer, according to a study published in Cancer Cell. Concerns surrounding the vaccination of this population stemmed from the effects that cancer and its treatments can have on the immune system, but the investigators said this study should alleviate those fears.

“This study confirms that there is no need for patients to wait for vaccination until they finish their chemotherapy or immunotherapy,” said Balazs Halmos, MD, MS, director of the Multidisciplinary Thoracic Oncology Program at Montefiore, in a press release. "The side effects from vaccination seen in these populations were not substantially worse than in other groups. Not a single patient had to go to the emergency room or be admitted to the hospital because of side effects from the vaccines.”

The study reviewed 200 patients with a wide spectrum of cancer diagnoses and found that after full vaccination, 94% of patients overall demonstrated seroconversion, which was determined by the presence of antibodies to the SARS-CoV-2 spike protein. Response rates were very high in patients with solid tumors and lower in individuals with certain blood cancers. However, even the majority of the latter group mounted an immune response.

“Studies from early in the pandemic found that cancer patients who get COVID-19 have higher rates of morbidity and mortality compared to the general population,” said Amit Verma, MD, director of the Division of Hemato-Oncology at Montefiore, in the release. “We really need efforts to protect these vulnerable patients from infection. This study should help people feel reassured that these vaccines work very well, even in those receiving chemotherapy or immunotherapy.”

Among patients with solid tumors, 98% showed seroconversion, whereas patients with hematologic cancers had an 85% rate of seroconversion. Patients receiving certain treatments had worse results, with those receiving therapies for blood cancers that work by killing B cells (such as rituximab or chimeric antigen receptor T-cell therapies) having seroconversion rates of 70%. The rate was 74% for those who had recently had bone marrow or stem cell transplants. According to the study authors, these rates were still higher than anticipated.

“Although those receiving treatments that affect B cells didn't do as well, patients with blood cancers that affect the myeloid cells rather than the lymphoid cells had a pretty good response with regard to seropositivity,” said Astha Thakkar, MD, in the release. “This includes people with acute myeloid leukemia and myelodysplastic syndrome.”

The investigators said part of what makes these data significant is that they include patients who had a broad range of cancers and who were undergoing a number of different treatments.

“Vaccination among these populations have been lower, even though these groups were hardest hit by the pandemic,” Verma said in the release. “It's important to stress how well these patient populations did with the vaccines.”

REFERENCE

Study confirms safety and effectiveness of COVID-19 vaccination in people with cancer [news release]. EurekAlert; June 9, 2021. Accessed June 10, 2021. https://www.eurekalert.org/pub_releases/2021-06/cp-scs060921.php