Summary of COVID-19 vaccination among King County residents

Data notes

Vaccination data are from the Washington State Immunization Information System (WAIIS). Due to reporting lags, all data are preliminary and subject to change. Data will be refreshed retrospectively with ongoing data quality improvements.

Demographics

Demographic data (age, race/ethnicity, and residential area) are also from WAIIS. Missing demographic data in WAIIS are supplemented with demographic data from case reporting where available.

Definitions of key terms on this dashboard

Original vaccine series refers to the original COVID-19 vaccine formulations which were designed to target the original virus that causes COVID-19. The original series, previously called the primary series, ranged from 1-3 doses depending on the vaccine manufacturer and person’s age. The original vaccine series was first authorized in December 2020. As of April 18, 2023, these original vaccines are no longer recommended in favor of updated vaccine formulations.

Original booster refers to any additional dose of the original vaccine given after the original series. The original vaccine formulations were designed to target the original virus that causes COVID-19. These original booster doses were first authorized by the FDA on August 31, 2021. As of August 31, 2022, they are no longer recommended, in favor of the updated formulations.

2022-2023 bivalent vaccine refers to any dose of the 2022-2023 bivalent formulation, which targeted the BA.4 and BA.5 lineages of the Omicron variant in addition to the original strain of the virus that causes COVID-19. The 2022-2023 bivalent vaccine was first authorized by the FDA on August 31, 2022. 

2023-2024 vaccine refers to any dose of the 2023 formulation, which targets the XBB lineage of the Omicron variant of the virus that causes COVID-19. Doses are counted as the 2023-2024 formula when they have a 2023-2024 formula product code. The 2023-2024 vaccine was first authorized by the FDA on September 11, 2023, and is no longer recommended as of August 22, 2024. 

2024-2025 updated vaccine refers to any dose of the 2024 formulation, which targets the KP.2 strain of the JN.1 lineage of the Omicron variant. Doses are counted as the 2024-2025 formula when they have a 2024-2025 updated formula product code and are administered on or after the FDA authorization date on August 22, 2024. 

Residents recommended for the 2024-2025 updated vaccine refers to any King County resident who is 6 months old or older, as long as at least two months have passed since their most recent prior COVID-19 vaccination dose. 

Additional details on CDC's definitions of the different COVID-19 vaccine formulations and staying up to date with COVID-19 vaccination can be found on the CDC’s website. This page uses the CDC guidance released on 9/11/2024.

People with compromised immune systems

People with compromised immune systems have different recommendations for COVID-19 vaccines than people with healthy immune systems. Typically, more doses are recommended. However, we do not have data to identify recipients with a compromised immune system who therefore require more doses to achieve vaccination coverage. As a result, this dashboard may slightly overestimate the number of recipients who've completed a primary series and the number of recipients who are up to date. View dose recommendations from the CDC for people with compromised immune systems.

Percentages

To estimate coverage percentages, 2023 Population Interim Estimates (PIE) developed by Public Health – Seattle & King County are used. The estimated 2023 King County population is 2,347,800 residents. Because we have applied PIE for different years to historic data, some estimated coverage percentages will be different from what we published previously. Vaccination counts from WAIIS may exceed population estimates and lead to greater than 100% estimated coverage, especially among populations with fewer residents or higher levels of misclassification of race or ethnicity. To reflect the level of precision of the coverage estimates, any coverage estimate above 95% is shown as ">95%."