COVID-19 vaccines are safe and effective for most cancer patients, a new study confirms.
Cancer patients have an increased risk of severe illness and death from COVID because their immune systems have been weakened by their disease or treatments.
"We pursued this study because there were limited data on the safety of SARS-CoV-2 vaccines in people with active cancer; no published prospective clinical trials included this patient population," said co-lead investigator Dr. Justin Gainor. He's director of the Center for Thoracic Cancers at Massachusetts General Hospital and associate professor at Harvard Medical School in Boston.
"There was also considerable uncertainty about how active treatment for cancer would affect the efficacy of the vaccines," Gainor said in a hospital news release. "Our data are reassuring on both safety and efficacy."
The study included more than 1,000 patients with a variety of solid-organ and blood cancers who had received two doses of the Moderna or Pfizer vaccines or one dose of the Johnson & Johnson vaccine. Thirty-two patients had also received vaccine booster doses.
As has been seen in healthy people, cancer patients who received the J&J vaccine had considerably lower immune responses than those who received the Pfizer and Moderna mRNA vaccines.
But whichever vaccine they receive, most cancer patients' immune responses are likely sufficient to protect them from severe COVID-19, according to findings published online Nov. 9 in the Journal of Clinical Oncology.
"Our data suggest that patients with cancer should receive mRNA vaccines," Gainor said. "In addition, patients who received the J&J vaccine should be considered for additional vaccine doses."
Additional doses of the vaccine in the small number of patients who received them were safe and triggered a stronger immune response, the researchers found.
The U.S. Centers for Disease Control and Prevention recommends that people who are immunocompromised -- including cancer patients -- receive additional doses of vaccine.
The study also found that cancer patients who had prior COVID infection had stronger immune responses to vaccination. Older age predicted weaker responses, and immunity triggered by all the vaccines declined over time.
Cancer treatment had a smaller effect on immune responses than the type of vaccine that patients received.
Those who received chemotherapy, bone marrow transplants or corticosteroids had weaker immune responses, but researchers believed that most were still protected. Patients who received treatments with immune checkpoint blockade (a type of immunotherapy) tended to have stronger immune responses.
"The vaccine side effects experienced by patients with cancer were similar to those experienced by healthy controls and were generally mild or moderate, which should be reassuring to patients," said co-lead investigator Dr. Vivek Naranbhai, a clinical fellow at Massachusetts General Hospital and the Dana-Farber Cancer Institute in Boston.
Patients who reported worse side effects had slightly better immune responses, and those with prior COVID-19 infection also had more significant reactions to the vaccine.
The American Cancer Society has more about COVID-19 vaccines for people with cancer.
SOURCE: Massachusetts General Hospital, news release, Nov. 10, 2021