The delta variant is spreading quickly among people who are not vaccinated. Author: Pat Dooris Updated: 6:11 PM PDT July 29, 2021 PORTLAND, Oregon — The surging delta variant of COVID-19 makes up at least 88% of all cases in Oregon, according to Brian O’Roak, a co-leader of Oregon Health and Sciences University’s (OHSU) Genome Sequencing Center. The center is currently studying and tracing different variants of COVID-19 in the state. The delta variant is an descendant of the novel coronavirus first detected in Oregon 16 months ago. There is reason to fear it, especially if you are not vaccinated, said Dr. Paul Cieslak from the Oregon Health Authority.