Researchers have found that repeated COVID-19 vaccination may increase the vaccine’s effectiveness at preventing the infections in patients with lymphoma, particularly after four doses, according to a new study published by Wijaya et al in The Lancet.
Background
Patients with lymphoma often have compromised immune systems—either as a result of the cancer or from treatments—leaving them more vulnerable to COVID-19 infections than other individuals and raising questions over how well they may respond to vaccination.
Study Methods and Results
In the new 2-year PROSECO study, the researchers recruited 524 patients with lymphoma from 2021 to 2022 and collected blood samples before the patients’ first vaccination and then at several intervals after their first, second, third, and fourth doses. The researchers then examined the link between antibody levels and T-cell responses with COVID-19 infections and symptom severity—with the aim of evaluating the strength of the patients’ immune responses to the vaccine and how effective that may have been at protecting them from COVID-19 infections.
The researchers discovered that the fourth dose of the COVID-19 vaccine generated antibodies that were more effective than those generated after the third dose, suggesting that higher quality antibodies were potentially produced with each increasing vaccine dose, resulting in a lower antibody level required to successfully fight the COVID-19 infections. The researchers also observed that 56% (n = 5/9) of the patients hospitalized with COVID-19 infections had absent T-cell responses compared with only 16% (n = 7/45) of those who were infected but did not require hospitalization.
Conclusions
“While the threat from COVID-19 [infections] is greatly reduced for most of us, for those with weakened immune systems, such as patients [with hematologic malignancies], the risk remains very real. Our findings support the need for immunocompromised patients to continue booster vaccinations to maintain a high level of protection,” emphasized senior study author Sean Lim, PhD, MBChB, Associate Professor of Haem-Oncology at the Centre for Cancer Immunology at the University of Southampton. “The PROSECO study also shows that antibody testing, and potentially T-cell testing, can help establish the risk of COVID-19 [infections] for patients with lymphoma at an individual level,” she highlighted.
The researchers noted that the new STRAVINSKY study is expected to begin recruiting by early August 2023. In this study, researchers will investigate whether antibody testing can also identify patients who remain at greatest risk of severe COVID-19 infections after vaccination in vulnerable populations beyond patients with lymphoma.
Disclosure: The research in the PROSECO study was funded by the Blood Cancer UK Vaccine Research Collaborative. The new STRAVINSKY study was funded by the National Institute for Health and Care Research. For full disclosures of the study authors, visit thelancet.com.
