PORTLAND, Ore. — Of the more than 700,000 Oregonians fully vaccinated against COVID-19, 168 of them still tested positive for the virus and three have died as of April 2, state health officials said Thursday.
The Oregon Health Authority (OHA) said these so-called "breakthrough cases" are reported when people test positive for COVID-19 at least 14 days after their final dose of a vaccine series.
They have been reported in 25 of the state's 36 counties, but they represent "a very small proportion" of the total number of Oregonians who've been fully vaccinated, OHA said in a news release.
"While the Pfizer, Moderna and Johnson & Johnson COVID-19 vaccines are all highly effective at preventing severe COVID-19 illness and death, no vaccine is 100% effective, and vaccine breakthrough cases will occur," the release says.
Health officials said many of the breakthrough cases were asymptomatic and were tested for other reasons. They said 11% of the breakthrough cases were hospitalized within 30 days following their positive test, and most occurred in people older than 65 or with underlying health conditions.
"The three deaths represent fewer than 2% of the vaccine breakthrough cases," OHA said, adding that "none of the vaccine breakthrough cases were associated with a COVID-19 variant."
To prevent vaccine breakthrough cases, OHA recommends basic COVID safety precautions like masking, physical distancing and avoiding social gatherings.
State and local epidemiologists are continuing to track and investigate vaccine breakthrough cases and are working closely with the Centers for Disease Control and Prevention to collect information that may provide insight into characteristics associated with vaccine breakthrough.
On March 30, Washington state health officials reported 102 breakthrough cases out of 1.2 million fully vaccinated people.