COVID-19 Vaccine Breakthrough Cases in Oregon

Oregon Health Authority has identified 168 COVID-19 vaccine breakthrough cases—when vaccinated individuals test positive for the virus—through April 2, including three deaths.

OHA public health officials say it’s a reminder that 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.

These cases have been reported in 25 counties and all health care preparedness regions (Region 1: 76; Region 2: 29; Region 3: 27; Region 5: 9; Region 6: 4; Region 7: 17; Region 9: 6). OHA is not reporting the regions in which the deaths took place. Multnomah County is Region 1; view map of regions here.

Vaccine breakthrough cases are defined as instances in which an individual received a positive COVID-19 test result at least 14 days after the final dose of any COVID-19 vaccine series. Vaccine breakthrough cases can be prevented by basic public health interventions, such as masking, physical distancing and avoiding social gatherings.

The number of vaccine breakthrough cases identified in Oregon represents a very small proportion of the more than 700,000 people in Oregon who have been fully vaccinated against COVID-19. Many of the vaccine breakthrough cases identified experienced asymptomatic infection and were tested for other reasons. Eleven percent (n=19) of the vaccine breakthrough cases were hospitalized within the 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, and none of the vaccine breakthrough cases were associated with a COVID-19 variant.

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.