By LAURAN NEERGAARD AP Medical Writer

New U.S. studies show COVID-19 vaccines remain highly effective against hospitalizations and death.

That's even against the extra-contagious delta variant. The Centers for Disease Control and Prevention tracked over 600,000 coronavirus cases in 13 states.

As delta surged over the summer, those who were unvaccinated were four times more likely than the fully vaccinated to get infected.

The unvaccinated were also over 10 times more likely to be hospitalized and 11 times more likely to die.

But as earlier data has shown, protection against coronavirus infection is slipping some.

The CDC studies were released Friday.