Cell-based immune anticipation of the omicron variant in SARS-CoV-2 triple-vaccinated cancer patients.

SARS-CoV-2 infections affect healthcare systems worldwide. Patients with cancer, a particularly vulnerable group, and oncology care takers were offered early access to mRNA-based vaccinations. We report the dynamics of humoral and cellular immune response parameters of 74 patients with cancer and 12 control participants after two basal vaccinations and a booster six months later. Upon booster vaccination, 78% of patients with tumor under active therapy (versus 50.8% prior to the boost) exhibited humoral and cellular spike protein responses, as compared to 100% and 73.3%, respectively, in those without active therapy. Conducted prior to the emergence of the Omicron variant of concern, we found Wuhan-Hu-1 spike-encoding mRNA vaccination to evoke T cell responses against peptides outside and within the Omicron-mutated region of the spike protein. The vast majority of patients with cancer achieved significant antibody titers upon repeated vaccinations. Accordingly, patients with tumor appeared well-protected, indicated by asymptomatic or mild breakthrough infections during the Omicron wave.