Currently City of Seattle is only vaccinating people who have not received a first dose. These sites offer the Moderna and Pfizer COVID-19 vaccines. The Moderna and Pfizer vaccines are not interchangeable.
The Moderna vaccine is only for patients 18 years-old or older. The Pfizer vaccine is only for patients 16 years-old or older.
You can register for COVID-19 Vaccination using the link below :
https://seattle.signetic.com/home/93d64636-e4a2-eb11-b1ac-002248089768
The article below explains how to register for COVID-19 vaccination via provided link :
Vaccination-Registration-Guide