According to a Kaiser Family Foundation analysis of official US state data, less than 1% of fully vaccinated people experienced a breakthrough infection lately, a CNN report said. 
The US federal government has been reporting data about breakthrough infections, which result in hospitalisation or death. 
The US Centers for Disease Control and Preventions latest data says, less than 0.004% people, who have been fully vaccinated against coronavirus experienced a breakthrough case resulting in hospitalisation, while less than 0.001% died. Out of more than 163 million fully vaccinated people in the US, it is about 6,600 severe cases. The analysis shows breakthrough infections are extremely rare. 
Around half of US states reported data on the breakthrough cases. In each state, less than 1% of fully vaccinated people got a breakthrough infection. It ranged from 0.01% in Connecticut to 0.9% in Oklahoma. 
The analysis also said over 90% of cases and more than 95% of hospitalisations and deaths have been reported among unvaccinated people. 
Meanwhile, CDC Director Dr Rochelle Walensky said the seven-day average of daily coronavirus cases in the country surpassed the peak set last summer. “COVID-19 is clearly not done with us and so, our battle must last a little longer, Walensky said.