PORTLAND, Ore. – Four breakthrough cases of COVID-19 have been found in Oregon.

Breakthrough is when someone is infected with the virus at least two weeks after being fully vaccinated.

The Oregon Health Authority says two of the cases are in Yamhill County and two are in Lane County.

The symptoms range from none at all to mild.

Here’s more from the OHA:

OHA today announced the discovery of four “breakthrough” cases of COVID-19. These are cases where an individual has tested positive for COVID-19 at least 14 days after completing their vaccination series.

Two of the cases are in Yamhill County and two are in Lane County. OHA is working with local public health officials to investigate the origin. Their illnesses range from asymptomatic to mild symptoms.

Genome sequencing is underway, and we expect results next week.

Such cases are not unexpected. 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.

Based on what is known about vaccines for other diseases and early data from clinical trials, OHA experts believe the existing vaccines are very effective.

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