TOPLINE:
In individuals with low B-cell counts, T cells have enhanced responses to COVID-19 vaccination and may help prevent severe disease after infection.
METHODOLOGY:
- How the immune systems of B cell–deficient patients respond to SARS-CoV-2 infection and vaccination is not fully understood.
- Researchers evaluated anti–SARS-CoV-2 T-cell responses in 33 patients treated with rituximab (RTX), 12 patients with common variable immune deficiency, and 44 controls.
- The study analyzed effector and memory CD4+ and CD8+ T-cell responses to SARS-CoV-2 after infection and vaccination.
TAKEAWAY:
- All B cell–deficient individuals (those treated with RTX or those with a diagnosis of common variable immune deficiency) had increased effector and memory T-cell responses after SARS-CoV-2 vaccination, compared with controls.
- Patients treated with RTX who were vaccinated against COVID-19 had 4.8-fold reduced odds of moderate or severe disease. (These data were not available for patients with common variable immune deficiency.)
- RTX treatment was associated with a decrease in preexisting T-cell immunity in unvaccinated patients, regardless of prior infection with SARS-CoV-2.
- This association was not found in vaccinated patients treated with RTX.
IN PRACTICE:
“[These findings] provide support for vaccination in this vulnerable population and demonstrate the potential benefit of vaccine-induced CD8+ T-cell responses on reducing disease severity from SARS-CoV-2 infection in the absence of spike protein–specific antibodies,” the authors wrote.
SOURCE:
The study was published online on November 29 in Science Translational Medicine. The first author is Reza Zonozi, MD, who conducted the research while at Massachusetts General Hospital, Boston, and is now in private practice in northern Virginia.
LIMITATIONS:
Researchers did not obtain specimens from patients with common variable immune deficiency after SARS-CoV-2 infection. Only a small subset of immunophenotyped participants had subsequent SARS-CoV-2 infection.
DISCLOSURES:
The research was supported by grants from the National Institutes of Health, the Centers for Disease Control and Prevention, the Howard Hughes Medical Institute, the Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, and Harvard Medical School, the Mark and Lisa Schwartz Foundation and E. Schwartz; the Lambertus Family Foundation; and S. Edgerly and P. Edgerly. Four authors reported relationships with pharmaceutical companies including AbbVie, Bristol-Myers Squibb, Boehringer Ingelheim, Gilead Sciences, Merck, and Pfizer.
A version of this article first appeared on Medscape.com.