Health officials in Oregon are investigating four cases in which people contracted the coronavirus after receiving both doses of the vaccine.
The symptoms of the four individuals range from asymptomatic to mild, the Oregon Health Authority said in a statement on Friday.
“We are working with our local and federal public health partners to investigate and determine the source of the case. Genome sequencing is ongoing and we expect results next week.” said the agency.
These individuals were called “innovative cases” because they fell ill with the new virus at least 14 days after receiving the second dose of the Covid-19 vaccine.
The Health Authority said such cases were not “unexpected” during the pandemic. “Clinical trials of both vaccines currently in use included innovative cases. In those cases, even though participants took Covid-19, the vaccines reduced the severity of the disease,” said the agency.
Two of the cases were discovered in Yamhill County and two others are in Lane County. Local health officials were now seeking to determine the source of these cases to provide the public with more information.
The announcement in Oregon comes at the time when a revealing case was revealed in North Carolina, according to NBC WCNC-TV affiliate in Charlotte.
State health officials told the outlet that the person had mild symptoms and was not hospitalized by Covid-19.
Pfizer and Moderna are the only two companies that have received emergency use authorization for their Covid-19 two-dose vaccines from the Food and Drug Administration (FDA). Studies indicate that each is about 94% effective against Covid-19 and reduces severe symptoms that can occur after contracting the new virus.
The Center for Disease Control and Prevention (CDC) has updated its guidance to state that people who are fully vaccinated no longer need to be quarantined if exposed to someone with Covid-19. Typically, people are asked to isolate themselves for one to two weeks if exposed.
But those who are fully vaccinated, that is, it has been two weeks since they received the second dose of the vaccine, no longer need to be quarantined until they develop symptoms.
Vaccinated people should follow other safety measures against the coronavirus, such as wearing masks, practicing social detachment and avoiding large crowds.