Health care workers (HCW) are at an increased risk since they are directly exposed to SARS-CoV-2 infected MESHD
patients, nevertheless, some remained without the development of anti-SARS-CoV-2 antibodies, suggesting lesser susceptibility to infection1-5. This study aimed to ascertain a potential specific cellular immune response to SARS-CoV-2 in these largely exposed HCWs.In this cross-sectional, case-control study, we analyzed 39 exposed uninfected HCWs and 17 convalescent HCWs. Cellular immune response was evaluated after SARS-CoV-2 stimulation with peptide pools ( proteins S PROTEIN
, M, and N), using bead-based multiplex assay (12 cytokines).Overall, 94.8% of uninfected HCWs had some degree of specific cellular response to SARS-CoV-2 structural proteins that could be classified, according to the number of cytokine production, as strong (61.5%), partial (33.3%), and weak/no response (5.1%). Strong responders showed a higher anti-inflammatory cytokine production ( IL5 HGNC
and IL10 HGNC
, p<0.001 and 0.002, respectively), and similar ( IFN-γ HGNC
and TNF-α HGNC
, p=0.435 and 0.532, respectively) or higher (IL12, p=0.021) pro-inflammatory production compared to convalescents, resulted in a predominantly Th2 response. This study demonstrated a consistent and polyfunctional immune cellular response after stimulation with SARS-CoV-2 peptides in extensively exposed individuals that should be considered to establish the infection susceptibility, the impact in herd immunity, and the risk of relapses.