Breakthrough COVID cases: Doctor explains your chances of contracting virus after vaccination

MARIN COUNTY, Calif. (KGO) -- As the Delta variant spreads, we are learning more about breakthrough COVID-19 cases.

Numbers from the state and county health departments help put into perspective what the chances are of getting coronavirus after being vaccinated -- and just how risky it is.

According to the California Department of Public Health, 20.7 million Californians have been fully vaccinated. Roughly 14,000 of those people (about 1 in every 1,441) have since contracted COVID-19.

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A fraction of those, 843, have led to hospitalizations. Even fewer, 88, have led to death. (That number could even be less, as health officials caution that in some of these cases it is unclear if COVID-19 was the primary cause of death.)

In gist: It's still extraordinarily rare.

"It's important for people to recognize that the vaccine is very strongly protective against severe illness and death," Marin County public health director Dr. Matt Willis told ABC7 News. "And when we are seeing these breakthrough cases they are asymptomatic, no symptoms at all, or mildly symptomatic like cold symptoms."

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Marin County has 206,580 vaccinated residents. According to Dr. Willis, only 177 have since contracted COVID-19. Of those, three people were hospitalized from the breakthrough cases, but there have been no deaths.

He says a vast majority of the hospitalizations of vaccinated people are among the elderly or immunocompromised.

He also says the county has seen no association between the type of vaccine a person received and whether they are at higher risk for a breakthrough case.

Across the Bay Area, it's a similar story. ABC7 News reached out to all nine counties in the region. Of those that responded (San Francisco, San Mateo, Napa and Sonoma),only Sonoma County reported deaths among vaccinated people.

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Sonoma County's health department says of the 475 breakthrough cases, there have been 23 hospitalizations and two deaths. Both people who died were older than 90, with significant underlying health conditions.

Dr. Willis says people need to remember immunity should be thought of as a continuum, and the vaccine as a dimmer switch.

"It's more like a dimmer switch than it is a light switch. It's not an on and off. It's on a continuum of protection," he said. "And I think that's an important message because otherwise, people might interpret breakthrough cases as a sign the vaccine is not effective."


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