How omicron fueled an unprecedented wave of breakthrough infections in WA

When the first COVID-19 vaccines began to arrive in Washington more than a year ago, the jubilation was evident. People traveled far at first to find a hard-to-come-by shot, with a hope that the end of the pandemic, or at least its deadliness, was near.

For those inoculated against the coronavirus, it was fairly uncommon to later test positive.

Then the variants hit.

These so-called “breakthrough” infections started popping up throughout the country last summer. As vaccination rates climbed and infections persisted, concern grew. At the time, the delta variant was overwhelming the region’s health care systems. Then the highly infectious omicron variant landed in the state and breakthrough cases nearly doubled.

By the end of January, Washington state had reported 342,195 breakthrough infections. About 75% of those had occurred within the prior two months. According to the state Department of Health, about 19% of people with breakthrough infections reported symptoms, while about 2% were hospitalized. Less than 0.5% died. Unvaccinated COVID patients, meanwhile, are five to seven times more likely to be hospitalized because of the virus, depending on age.