A new study helps quantify the improved protection against COVID-19 achieved with a third booster dose of the vaccine from Pfizer Inc and BioNTech SE in cancer patients who are undergoing chemotherapy.
“Chemotherapy can weaken the ability of cancer patients to fight off infections and to respond appropriately to vaccines,” said Deepta Bhattacharya of the University of Arizona College of Medicine, coauthor of the study reported in Nature Medicine.
Her team studied 53 patients receiving chemotherapy for solid-tumor cancers who received two shots of the vaccine. Almost all of the subjects had an immune response after vaccination.
But “the magnitude of these responses was worse than in people without cancer in almost every metric that we measured,” Bhattacharya said. “In all likelihood, this leaves cancer patients more susceptible to infection and COVID-19 than healthy vaccinated people.”
The researchers were able to bring back 20 of the study participants for a third vaccine dose, to see if immune responses would improve. “The levels of antibodies improved in about 80% of the cancer patients,” Bhattacharya said.
“Our data on cancer patients supports the CDC’s broad guidelines that people who are immunocompromised should receive a third dose of the Pfizer vaccine.”
Photo – EPA-EFE/VOLODYMYR PETROV