Public health officials announced Thursday that a total of 611 people in Oregon have tested positive for COVID-19 even though at least two weeks had passed since they’d finished their full courses of vaccinations.
Eight of those people died, with each age 70 or older.
Officials with the Oregon Health Authority said these cases represent a “very small” percentage — about .047% — of the 1.3 million Oregonians who’ve completed the one- or two-dose courses of the Johnson & Johnson, Pfizer or Moderna regimens.
But some of the 611 cases in Oregon could be an overcount because the definition of these so-called “breakthrough cases” is problematic, said Dr. Melissa Sutton, who oversees COVID-19 testing for the Oregon Health Authority.
That’s because a person isn’t truly considered fully vaccinated until 14 days have passed after receiving one dose of Johnson & Johnson’s vaccine or two doses of the Pfizer and Moderna vaccines. Yet the Centers for Disease Control and Prevention has defined a “breakthrough case” as someone who tests positive after at least 14 days have passed since that final shot.
That means a person could have been infected two to 14 days earlier than their positive test, when the vaccines hadn’t had enough time to reach their peak effectiveness.
Sutton said the Oregon Health Authority continues to report these as breakthrough cases because it is obligated to follow the CDC definition. The agency has the ability to look closer at its breakthrough cases and deaths to determine when the test result came back positive but has yet to do so, officials said.
Thursday’s numbers include the 168 “breakthrough cases” and three deaths the state reported in early April, the first time it began reporting the cumulative number of cases in Oregon. That means officials identified 443 new cases and five new deaths from early April to early May.
Of the total number of breakthrough cases in Oregon, about 50% showed no symptoms.
About 7% of them — or 45 people — were sick enough to be hospitalized. Close to 15% were people living in nursing homes or other long-term care facilities.
The eight deaths amount to 1.3% of the cases.
About 2% of cases — or 11 people — were linked to the variants of concern first identified in California (B.1.427 and B.1.429), South African (B.1.351) or Brazil (P.1.). No cases were linked to the variant first detected in the United Kingdom, B.1.1.7.
Nationwide, the CDC has reported more than 9,200 breakthrough cases, 835 hospitalizations and 132 deaths, but that most likely is an undercount under the CDC’s definition of cases because a portion of cases most certainly go undetected, with their carriers never getting tested.
On top of that, the CDC recently has asked states to report only breakthrough cases with serious health consequences — those requiring hospitalizations or resulting in death, according to the Oregon Health Authority. The health authority, however, has decided to continue to report cases, as well. It does so on a monthly basis, with the next report due out in early June.
Officials at the health authority and the CDC say the current vaccines in use are highly protective. Officials expect a small number of breakthrough cases because no vaccine is 100% effective. In the U.S. the Pfizer and Moderna vaccines have been shown to be 94% and 95% effective in preventing symptomatic disease, and Johnson & Johnson 72%.
— Aimee Green; [email protected]; @o_aimee