Thousands of vaccinated people in U.S. infected with COVID-19

COVID-19 infections have occurred in about 5,800 people in the United States who have been vaccinated against the virus, the U.S. Centers for Disease Control and Prevention says.

But "vaccine breakthrough" infections were expected among the estimated 77 million people in the United States who are fully vaccinated against the new coronavirus, officials added. In clinical trials, none of the vaccines were 100 percent effective in preventing infections. The agency told CNN that 7 percent of people with these vaccine breakthrough infections had to be hospitalized and 74 died.

"Vaccine breakthrough infections were reported among all people of all ages eligible for vaccination. However, a little over 40 percent of the infections were in people 60 or more years of age," the CDC said. Of the breakthrough infections, 65 percent occurred in women and 29 percent were asymptomatic, CNN reported. The agency said it will try to identify vaccinated people most at risk for breakthrough infections.

The new data are the first to indicate how effective COVID-19 vaccines are in real life and the first to show that they do not completely protect against severe illness and death, CNN reported. Breakthrough infections are not unexpected, and more will occur as the number of people who are vaccinated increases.