(Portland, OR) -- Health officials say more than 100 Oregonians have tested positive for COVID-19 despite being fully vaccinated against the virus. The Oregon Health Authority confirmed 168 so-called breakthrough cases across 25 counties yesterday. The agency says three of those people died. Health officials say the number is a small fraction of the more than 700-thousand Oregonians who are fully vaccinated against COVID-19. They add they're not worried or surprised by the breakthrough cases, since the vaccine is not 100-percent effective.