NEW YORK (Reuters Health) - Most cancer patients, including those with blood cancer, who had no measurable immune response after two doses of COVID-19 vaccine generated immune responses after a booster shot, researchers report.
"Following the booster, we show a broad boosting of antibody titers in patients with both solid tumors and hematologic malignancies," Dr. Lauren Shapiro with Montefiore Medical Center/Albert Einstein College of Medicine, in New York City, told Reuters Health by phone.
"The most impressive thing that we showed was that the majority of patients with hematologic malignancies, who may not respond to vaccination as well as others, actually had a significant increase in their ability to mount an immune response after the booster dose, especially for those who had no evidence of any antibody immune response after the initial vaccination series," she said.
The findings appear in Cancer Cell.
Dr. Shapiro and her colleagues studied two groups of cancer patients. The first group included 99 patients who were fully vaccinated against COVID-19. While most had detectable antibody levels after completing either the Pfizer or Moderna two-shot series, antibody levels declined four to six months after the second dose.
The second group included 88 fully vaccinated patients who were tested for the presence of antibodies before and after a booster dose. Sixty-four percent of these patients had detectable antibodies prior to the booster shot, while the remaining 36% (all but one of whom had blood cancer) tested negative for antibodies.
All 88 patients received a COVID-19 booster dose and four weeks later, 79.5% had antibody levels that were higher than before the booster shot. Notably, 56% of cancer patients who previously had no detectable antibodies after initial vaccination mounted an immune response to the booster shot, the authors report.
"We show evidence of waning immunity four to six months after initial vaccination, and that we were able to significantly boost that immunity with the booster vaccine," Dr. Shapiro told Reuters Health.
Most patients received a full-dose Pfizer or Moderna booster because at the time of the study, there was not a half dose available, she noted.
"Our study demonstrates in clear terms how the booster shot can make all the difference for some people with compromised immune systems, such as people with cancer," Dr. Balazs Halmos with Montefiore Health System and Albert Einstein College of Medicine, who also worked on the study, said in a statement.
"We recommend COVID-19 vaccination for the majority of patients with cancer," Dr. Shapiro told Reuters Health.
"Obviously, we always want patients to consult with their oncologist prior to decision making, but based on our research, we think vaccinating against COVID-19, including the booster dose, is one of the most important things that cancer patient can do and they should anticipate responding to them well, even similar to the general population," she added.
SOURCE: https://bit.ly/3nHNis0 Cancer Cell, online November 15, 2021.