Doctors at Yale Medicine say while new COVID-19 cases continue to fall, the more transmissible delta variant is on the rise in Connecticut.

They say 1 out of 8 cases in the state are due to the variant.

Dr. Richard Martinello says it may spread 60% more easily than earlier COVID-19 variants and could pose a higher risk of hospitalization.

New data from Israel suggests the Pfizer vaccine may not be as effective at fighting the new variant.

Martinello says all three vaccines in use in the U.S. are still great at protecting you from severe illness or death.

"What's been shown is that the vaccine is still highly effective, especially to preventing people from getting sick enough to be hospitalized if they do get ill with this delta variant,” he says.

Doctors say there's still research to be done on the constantly evolving virus.

In the meantime, Martinello says it's still best to exercise caution if you're going to be in a crowd.

"While being fully vaccinated gives us a good degree of protection, it's not perfect, so we still need to keep our masks handy,” he says.

Doctors say COVID-19 vaccines are more available than ever, and state officials now say more than 60% of Connecticut residents are fully vaccinated.

A Yale School of Public Health report released on June 1 found more than 13% of Connecticut cases sequenced came from the delta variant – up from less than 3% the week before.