To the Editor, we would like to share ideas on the publication “Cellular and humoral immune response to SARS-CoV-2 mRNA vaccines in patients treated with either Ibrutinib or Rituximab [1].” Even while the serological response to the SARS-CoV-2 vaccination is substantially compromised in patients treated with B-cell-targeting therapy, Bacova et al. determined that the majority of these patients generate adequate cell-mediated immunity. As a result, immunization of these patients could be beneficial in terms of preventing SARS-CoV-2 infection [1]. We agree that the mRNA vaccination has the potential to elicit an immunological response. The potential confounding factor due to asymptomatic COVID-19 is a major worry in the current report. Asymptomatic COVID-19 is not uncommon, and asymptomatic COVID-19 can occur before or after vaccination [2]. The asymptomatic COVID-19 can make it difficult to evaluate the immunological markers being investigated.