Antibody Response, Cellular Immune Response, SAR-CoV-2
Conditions
Brief summary
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.
Interventions
OTHEREvaluation of the T cell response in terms of IFN-γ measured by ELISpot
The evaluation of the T cell response will be performed by quantifying the frequencies of SARS-CoV-2-specific T cells producing IFN-γ using an enzyme-linked immunospot assay (ELISpot), with cryopreserved PBMC collected at the designated timepoints (T0, T1, T2, T3, and T4)
Sponsors
IRCCS San Raffaele
Study design
Observational model
COHORT
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| To assess the existence of a correlation between the antibody titer six months after the second dose and the T and B cell responses | Six months after the second vaccine dose, which coincides with the time of enrollment | Correlation between antibody titer, in terms of antibodies directed against the Spike protein, and T cell response, in terms of IFN-γ measured by ELISpot, as well as B cell response, in terms of frequency and phenotype, assessed six months after the second dose (T3) |
Countries
Italy
Outcome results
None listed