Natural History of Systemic and Nasal Mucosal Immunity to Influenza and SARS-CoV-2 in Adults After Vaccination

Study Description: Yearly influenza vaccination is necessary due to short-lasting influenza immunity and changing strains of circulating influenza. With limited effectiveness of yearly influenza vaccines and the ongoing potential for an influenza pandemic, there is a need for a better understanding of influenza immunity to develop improved vaccines. Severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) vaccines have been developed in response to the coronavirus disease 2019 (COVID-19) pandemic. There is a critical need to also understand the changes in long-term immunity in those who receive a SARS CoV-2 vaccine to develop improved vaccines. We will investigate the changes in long-term immunity of NIH workers after vaccination with influenza and/or SARS-CoV-2 and throughout the following year via blood and nasal sampling. Objectives: Primary Objectives: Characterize the systemic anti-influenza humoral immune response to vaccination over 1 year. Characterize the systemic anti-SARS-CoV-2 humoral immune response to vaccination over 1 year. Secondary Objectives: Characterize the nasal mucosal anti-influenza humoral immune response to vaccination over 1 year. Characterize the nasal mucosal anti-SARS-CoV-2 humoral immune response to vaccination over 1 year. Endpoints: Primary Endpoints: 1. Systemic anti-influenza antibodies as measured by: 1. Hemagglutination inhibition (HAI) antibody titers 2. Neuraminidase inhibition (NAI) antibody titers 3. Anti-Hemagglutinin (HA) head antibody quantitative enzyme linked immunosorbent assay (ELISA) (immunoglobulin \[Ig\] M, IgG, IgA) 4. Anti-HA stalk antibody quantitative ELISA (IgM, IgG, IgA) 5. Anti-Neuraminidase (NA) antibody quantitative ELISA (IgM, IgG, IgA) 2. Systemic anti-SARS-CoV-2 antibodies as measured by: 1. Anti-SARS-CoV-2 spike antibody quantitative ELISA (IgM, IgG, IgA) 2. Anti-SARS-CoV-2 receptor binding domain (RBD) antibody quantitative ELISA (IgM, IgG, IgA) Secondary Endpoints: 1. Mucosal anti-influenza antibodies from nasal samples as measured by: 1. Anti-HA head antibody quantitative ELISA (IgA, IgG) 2. Anti-HA stalk antibody quantitative ELISA (IgA, IgG) 3. Anti-NA antibody quantitative ELISA (IgA, IgG) 2. Mucosal anti-SARS-CoV-2 antibodies from nasal samples as measured by: 1. Anti-SARS-CoV-2 spike antibody quantitative ELISA (IgA, IgG) 2. Anti-SARS-CoV-2 RBD antibody quantitative ELISA (IgA, IgG) Study Population: NIH staff (N=100) who are 18 years and older. NIH staff may include employees and contractors, fellows and volunteers. Accrual ceiling N=150. Description of Sites/Facilities Enrolling Participants: Participants will be enrolled at the NIH Clinical Center (CC). Study Duration: 5 years