Only .01% of fully vaccinated Americans experienced breakthrough COVID infections through April, CDC says

The U.S. Centers for Disease Control and Prevention released data Tuesday that showed only a tiny portion of fully vaccinated Americans experienced a breakthrough COVID-19 infection between January and April.

The CDC defines a fully vaccinated person as someone who has received all recommended doses of any of the three FDA-authorized COVID vaccines. A breakthrough infection occurs when a fully vaccinated person tests positive no sooner than two weeks after receiving their final injection.

According to the CDC, approximately 101 million Americans were fully vaccinated at the end of April. Of that 101 million, only 10,262 breakthrough cases were reported in 46 states, which is equivalent to 0.01% of fully vaccinated people.

The findings echo the preliminary results of the vaccines’ clinical trials. Although the Pfizer, Moderna and Johnson & Johnson shots are highly effective at lowering the hospitalization and death rates of the pandemic, none of the trials concluded the jabs would make infections impossible.

The CDC said breakthrough infections were always expected and will remain "possible until population immunity reaches sufficient levels to further decrease transmission."

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"The number of COVID-19 cases, hospitalizations, and deaths that will be prevented among vaccinated persons will far exceed the number of vaccine breakthrough cases," the CDC said.

Sixty-three percent of the breakthrough infections occurred in women. The median age of breakthrough patients was 58 years old.

Twenty-seven percent of breakthrough patients were asymptomatic, 10% of them were hospitalized and 2% died.

The CDC said of the 995 hospitalized patients, 29% were asymptomatic or hospitalized for a reason not related to COVID-19. The average age of those who died was 82.

In this photo illustration, vials of fake 'Covid-19 Vaccine

In this photo illustration, vials of fake 'Covid-19 Vaccine' and a syringe seen displayed with a logo of Centers for Disease Control and Prevention (CDC) in the background. (Photo Illustration by Pavlo Gonchar/SOPA Images/LightRocket via Getty Images

The CDC acknowledges the number of breakthrough cases likely reflects a substantial undercount. They’re relying on data voluntarily submitted by states. And fully vaccinated people who feel ill are less likely to seek a COVID test.

Even so, the CDC transitioned from monitoring all breakthrough infections on May 1 to monitoring those that result in hospitalizations or deaths.

This story will be reported from Atlanta.