Patients with cancers of the blood have a significantly weaker antibody response to vaccines for COVID-19 than patients with solid tumors, but may be well protected against severe disease, the researchers reported at ASCO 2022, the annual meeting of the American Society of Clinical Oncology.
Researchers at Monash University in Australia studied immune responses after three doses of Moderna, Pfizer-BioNTech or AstraZeneca COVID vaccines in nearly 400 adults with active or recently treated cancers.
They found that only 3.2% of 256 patients with solid tumors lacked antibodies capable of neutralizing SARS-CoV-2 and preventing infection, compared to 30% of 137 with hematologic malignancies. However, T cell responses were similar regardless of cancer type.
Thus, T-cell responses may indicate immune protection “for those who do not have an antibody response,” the researchers noted.
The same team reported in another registered document that the data on the safety of COVID-19 vaccines for cancer patients “are reassuring”
Survey responses from nearly 500 adults and children showed that most experienced some side effects, with injection site pain and fatigue being the most common.
However, rates of serious reactions were low (between 0% and 10%) and interruptions of cancer treatment were rare (between 0% and 11%). “There were no significant changes in quality of life with doses 1 or 2 in children or adults,” the researchers noted.