Mechanisms of Anti COVID-19 Humoral and Cellular Immune Response After Vaccination in a Sample of Patients and Salaried Staff From a French Anti-cancer Center

The main objective of this study is to describe after anti-SARS-CoV-2 vaccination the humoral immune response against the virus (assay of anti-SARS-CoV-2 antibodies to detect the presence and intensity of humoral immune responses) and the cellular response against the virus (specific T response).

Several cohorts are studied:

• Cohort 1 of vaccinated salaried staff (First group : Employees vaccinated with two doses of vaccine (2 Pfizer doses or 2 Astra doses or 1 Pfizer dose + 1 Astra dose) and never infected with SARS-CoV-2) and second group (Employees vaccinated with one dose of Pfizer or Astra vaccine and previously infected with SARS-CoV-2)
• Cohort 2 of unvaccinated salaried staff (controls)
• Cohort 3 of vaccinated cancer patients (metastatic colorectal, metastatic pancreas and metastatic breast cancer)

Inclusion criteria

Group 1

• Salaried staff of the Georges-François Leclerc center over 18 years old
• Subject vaccinated against SARS-CoV-2 for at least 1 month (last injection), AND less than 4 months (last injection).
• Subject who gave his consent to this study
• Subject affiliated to a social security scheme

Group 2

• Salaried staff of the Georges François Leclerc center over 18 years old
• Subject not vaccinated against SARS-CoV-2
• Subject having presented a proven infection by SARS-CoV-2 (PCR)
• Subject who participated in the canSEROcov study with a positive serology result
• Subject who gave his consent to this study
• Subject affiliated to a social security scheme

Group 3

• Patient over 18 years of age treated in Oncology at the GF Leclerc center for:

• Metastatic colorectal cancer beyond the first line of treatment
• Metastatic pancreatic cancer as the first line of treatment
• Metastatic breast cancer treated with anti-CDK4 / 6 + hormone therapy, or localized breast cancer treated with (neo) adjuvant chemotherapy
• Patient vaccinated against SARS-CoV-2 for at least 1 month (last injection), AND less than 4 months (last injection) with a vaccination performed when the anti-cancer treatment had been started for at least 1 month (last injection) ) (see diagram below)
• Patient having signed the informed consent for the study
• Patient affiliated to the social security scheme

Exclusion criteria

Groups 1, 2 and 3

• Minor or under legal protection
• Person deprived of liberty or under guardianship (including curatorship)
• Inability to undergo medical monitoring of the trial for geographical, social or psychological reasons (filling in the questionnaire and taking the blood sample)
• Refusal of the patient or employee to participate
• pregnant or breastfeeding woman