Of more than 700,000 people in Oregon who have been fully vaccinated against COVID-19, 168 still tested positive for the virus and three died. The Oregon Health Authority says that while the vaccines are all highly effective, no vaccine is 100% effective. Vaccine breakthrough cases are instances in which a person received a positive COVID-19 test result at least 14 days after the final dose of any COVID-19 vaccine series. Many of the vaccinated people who tested positive for COVID-19 experienced asymptomatic infection. None of the vaccine breakthrough cases were associated with a COVID-19 variant.