Study of Immune Response in Subjects Vaccinated Against SARS-CoV-2 Infection

Monocentric Retrospective Observational Study on Immune Response in Biological Samples Belonging to Subjects Vaccinated Against SARS-CoV-2 Infection

Twelve months after the first SARS-CoV-2 cases in Wuhan, the FDA approved the first COVID-19 vaccine (Pfizer-BioNTech). Early studies on healthcare workers showed that antibody levels, especially against the Spike protein, declined within six months, particularly in those without prior infection. However, previously infected individuals had stronger and longer-lasting responses. The vaccine induces a Th1-type T cell response, linked to milder disease, and activates follicular helper T cells and B cell responses, although antibody levels drop over time. Immune responses also differ by sex, with females showing stronger humoral responses. Key priorities include understanding humoral fluctuations, characterizing cellular immunity, and correlating both responses.

healthcare workers group

Inclusion Criteria:

• Male and/or female sex

Age ≥18 years

Completion of the SARS-CoV-2 vaccination cycle with the Pfizer-BioNTech vaccine

Informed consent for the storage of biological material at the San Raffaele Hospital Biological Resource Center (with protocol related to the BioVAC study approved by the Ethics Committee: 17/INT/2022)

Availability of at least two aliquots of PBMC collected at the completion of the vaccination cycle and frozen at the CRB

Exclusion Criteria:

• none donor group

Inclusion Criteria:

- consent for sample collection and storage in the Biobank between 2016 and 2018

Exclusion Criteria:

• none