Every dose of COVID-19 vaccine that’s given in Okanogan county is entered into the Washington Immunization Information System (WAIIS). Information about the vaccine (type, lot number, expiration date, etc), the organization that gave the vaccine, and information about the person who received it, is all entered into WAIIS.
OCPH can count the number and type of vaccine doses given, and determine how many people have been vaccinated within each zip code. Based on population estimates of Okanogan county, we can then calculate the percentage of residents who have received the vaccine within each zip code.
Okanogan county is somewhat unique in Washington because, while our population is fairly small (43,130 full-time residents), it grows by over 10% each summer as seasonal workers arrive to work primarily in agriculture during the summer and fall. During the spring and summer of 2021, healthcare workers provided COVID-19 vaccines to over 5,000 H-2A workers who lived and worked in Okanogan county. Every one of those doses was also entered into the WAIIS system. So, during the summer, Okanogan county appeared to have a high number of vaccinated residents.
As of late November 2021, most of the seasonal workers have left Okanogan county. As such, OCPH has removed their numbers from the calculations of vaccinated residents. However, those doses are not removed from WAIIS, and the WA Department of Health COVID-19 vaccine tracker (here) still includes those individuals as vaccinated residents of Okanogan county.
The vaccine data presented on the OCPH data page (here) will be different from the WA DOH data for that reason.
Also, some people who receive a vaccine choose not to provide their contact information, so OCPH cannot assign them to a zip code. WAIIS also does not include vaccines given by Indian Health Services, because IHS has a separate vaccine tracking system.
OCPH will update the vaccine map each week here.