COVID-19 Booster and IIV Schedule in Immunocompromised Hosts

Inclusion Criteria: \- All participants must meet ALL the following inclusion criteria: i. Adults (≥18 years) ii. Received the primary mRNA COVID-19 vaccine series (i.e., ≥3 doses) iii. Have at least one of the following immunocompromising conditions: a) Received a solid organ transplant (SOT) ≥3-months ago, and treated with a conventional maintenance immunosuppression regimen; b) People living with HIV (PLWH) receiving ART for ≥6 months who meet at least one of the following conditions: i) AIDS-defining illness in the last 6 months, ii) TB diagnosis in the last 6-months, iii) CD4\&lt;200 cells/µL in the last 6 months, iv) CD4%\&lt;15% in the last 6 months, or v) absence of HIV viral suppression in the last 6 months; c) Inflammatory bowel disease (IBD) treated with a conventional or biologic immunosuppressive agent for ≥3 months; d) Rheumatoid arthritis or systemic lupus erythematosus (herein referred to as rheumatological disease (RD)) treated with a conventional or biologic immunosuppressive agent for ≥3 months. Exclusion Criteria: * Potential participants who meet ANY of the following criteria will be excluded: i. Received any of the following: 1. Annual vaccination against influenza \&lt; 6 months ago 2. COVID-19 booster \&lt; 3 months ago ii. History of any of the following: <!-- --> 1. life-threatening reaction any component of the IIV or COVID-19 vaccines 2. Guillain-Barre syndrome or myocarditis within 6 weeks of a previous influenza or COVID-19 vaccination 3. Contraindication to intramuscular vaccines such as bleeding disorder, severe thrombocytopenia, etc; iii. Receiving intravenous immunoglobulins; iv. Have underlying primary inborn errors of immunity; v. Receiving chemotherapy such as cyclophosphamide \&lt; 6-months ago; vi. Unable to provide informed consent