The purpose of this research study is to learn how the body forms a protective immune response after COVID-19 vaccination and how it responds to viral variants. This study is for people who plan to get a COVID-19 vaccine dose (either their first doses or a booster) but have not received it yet.

Participants will first have a screening visit (about 1 hour) to see if they qualify. If eligible, participants will have a visit before donation evaluation (about 30 minutes) and a leukapheresis visit (about 2.5–4 hours). Leukapheresis is a procedure that collects certain blood cells. Participants will then get their COVID-19 vaccination at a place of their choice, because the study team will not provide the vaccine. After vaccination, participants will return for several blood draw visits (about 30 minutes each) and a final leukapheresis visit (about 2.5–4 hours).

Participants may also choose to do optional procedures. These include a fine needle aspiration of lymph nodes under the armpit to study how antibodies are being made, and optional periodic blood draws or leukapheresis to see how immune protection holds up over time.

Who can participate:
People planning to receive a COVID-19 vaccine dose (first doses or a booster) may be able to participate if they:

• Plan to receive a COVID-19 vaccine or booster but have not gotten it yet
• Are willing to have blood draws

Study timeline and visits:
From screening, participation lasts around 9 months. There is 1 screening visit, 1 pre-donor evaluation visit, 2 leukapheresis visits, and 6 blood draw visits (9 visits total). Vaccination happens at a place you choose.