An international team of researchers surveyed 131 patients with cancer to review the immune response to mRNA Covid-19 vaccines. Among them, 94% developed antibodies to the coronavirus while seven high-risk patients didn't . the tiny group of patients who exhibited no response to the mRNA vaccines raised questions on how their protection against the virus are going to be addressed moving forward.
"We couldn't find any antibodies against the virus in those patients," said Dimpy P. Shah, MD, PhD, of the Mays Cancer Center, home to UT Health San Antonio MD Anderson. "That has implications for the longer term . Should we offer a 3rd dose of vaccine after cancer therapy has completed in certain high-risk patients?"
The median age of patients included within the survey was 63 and most of them (106) had solid cancers as against haematological malignancies (25). Pankil K. Shah, a co-lead author of the study, said that patients with haematological malignancies, like myeloma and Hodgkin lymphoma, were less likely to reply to vaccination than those with solid tumours.
Among the patients, those receiving Rituximab, a antibody utilized in the treatment of haematological cancers and autoimmune diseases, within six months of vaccination developed no antibodies. Patients on chemotherapy developed antibody response but it had been muted compared to the overall population.
“How that relates to protection against Covid-19, we do not know yet," Dr Dimpy Shah said.
The study suggests that patients with high-risk cancers should continue taking precautions even after being vaccinated. The findings of the study were published within the journal 'Cancer Cell'.
Limitations of the study
The highly transmissible Delta variant and other mutants weren't examined within the study. The team also didn't analyze the response of infection-fighting T cells and B cells in patients with cancer. The study population was 80% non-Hispanic white, 18% Hispanic and a couple of Black, which suggests immune response among Black may vary during a bigger sample size.
"We recommend that future studies be wiped out Black, Asian and Hispanic patients, as well, to ascertain if there are any differences in vaccination immune response," Dr Ruben Mesa, MD, FACP, executive of the Mays Cancer Center said.
