These results are noteworthy because it has been described that CVID individuals demonstrate a dysregulated B cell compartment, characterized by a reduction of class-switched memory B cells, and an increased frequency of atypical memory B cells (CD19+CD27-CD21-IgM-IgD-), which encompasses most Spike-specific memory B cells after COVID-19 vaccination.11 Here, CD27 is linked to common variable immunodeficiency.