'Breakthrough' COVID-19 reported in 4 fully vaccinated individuals

Health officials in Oregon said they are investigating four so-called "breakthrough" cases of coronavirus that were detected in individuals two weeks after they received their second dose of vaccine. The illnesses range from asymptomatic to mild, according to a news release posted Friday.

"Such cases are not unexpected," the news release said. "Clinical trials of both vaccines presently in use included breakthrough cases. In those cases, even though the participants got COVID-19, the vaccines reduced the severity of illness."

Genome sequencing is underway, and officials expect results next week. Two...