This is a prospective cohort study aimed to evaluate short- and mid-term immune response after SARS-CoV-2 vaccination using Gam-COVID-Vac (Sputnik V) vaccine in dialysis patients compared to the control group (medical staff).

Background and aims: Patients receiving kidney replacement therapy with dialysis are at high risk of infection and death from COVID-19. There is a lack of evidence whether SARS-CoV-2 vaccination is effective in this immunocompromised group.

Study design: this is a prospective cohort study. Two cohorts will be included: dialysis patients and controls (medical staff), both vaccinated with Gam-COVID-Vac (Sputnik V) vaccine.

Blood samples will be collected at 28 days and 22 weeks after after the second SARS-CoV-2 vaccine dose administration.

The primary outcome is the level of SARS-CoV-2 IgG antibodies on day 28 after the second vaccination as compared to controls.

The secondary outcomes are: 1) the level of SARS-CoV-2 IgG antibodies on week 22 after the second vaccination; 2) T cell subtype immunity measured by SARS-CoV-2 interferon-γ release assays (IGRA) 28 days and 22 weeks after the second vaccination.

Inclusion Criteria:

• Age of 18 years or older
• Previously vaccinated against SARS-CoV-2 with two administrations of Gam-COVID-Vac (Sputnik V) vaccine
• Written informed consent.

Exclusion Criteria:

• A history of previous COVID-19 disease
• Active malignancy of any localization
• Human Immunodeficiency Virus (HIV) infection
• Maintenance treatment with immunosuppressive therapy.

Subjects ≥ 18 years old who were vaccinated twice against SARS-CoV-2 using Gam-COVID-Vac (Sputnik V) vaccine.