Four Oregonians tested positive for COVID-19 after being vaccinated against the disease, Oregon health officials announced Friday.
The Oregon health authority said two of the cases were in Lane County and two in Yamhill County.
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Two of the cases were found during routine surveillance tests. It looks like the other two are connected. OHA officials did not specify which two.
“This is a serious but not surprising development,” said Patrick Allen, director of OHA.
These reinfections, called “breakthrough infections”, are infections that occur more than 14 days after receiving the second dose of vaccine.
Given the efficacy rate of the two vaccines – 95% for both Pfizer-BioNTechs and Modernas – it is inevitable that some of the 177,000 vaccinated Oregonians would be re-infected.
It is not yet known whether these four known re-infection cases involve a newer variant of the coronavirus. The Oregon Health Authority is trying to have samples from these patients tested, a process that can take more than a week.
The Centers for Disease Control and Prevention collects data on COVID-19 breakthrough cases, but they have yet to release the information. Oregon is one of the first states to participate in their genomics monitoring program, and has sent information about these cases to the CDC.
Many breakthrough cases were reported during the Moderna and Pfizer COVID-19 vaccination studies. These cases tended to be asymptomatic or mild, and so far Oregon’s cases fall into one of two categories.
State epidemiologist, dr. Dean Sidelinger, said this is good news, as the COVID-19 death toll for non-vaccinated Oregonians is nearly 3,000.
“Vaccinations prevent you from getting seriously ill, even if you do not get sick,” he said.
Sidelinger said these breakthrough cases underscore the importance of continuing to follow pandemic safety measures, such as wearing masks and taking social distances, even after receiving the vaccine. Until enough vaccinations have been given to bring about herd immunity – something that is still months away – breakthrough cases will continue to occur.