(WFSB) - People in Hartford, New Haven, and New London counties should be wearing masks indoors, regardless of their vaccination status, according to the Centers for Disease Control.

Tuesday, no counties in Connecticut met that requirement.

However, 24 hours later, New London and Hartford counties reached that threshold where they were considered to have a 'substantial' level of community transmission.

On Thursday afternoon, New Haven was added to the 'substantial' category.

People in Hartford and New London Counties should be wearing masks, regardless of their vaccination status.

Professor Santella from the University of New Haven’s health administration and policy weighed in on how life should change for those who in these counties.

"I think everyone should err on the side of caution and go back to the things we were so used to doing last year in terms of monitoring health, wearing masks, hand hygiene," explained Santella.

CDC classifies Hartford, New London Counties as high COVID transmission areas.

Until more people get vaccinated, this is going to be our life," added Santella.

That reemergence means the county is going back to the old guidelines.

Justin Elicker, Mayor of New haven said, "I know that’s disappointing for some people, but we’ve got to keep each other safe.”.

Channel 3 is also working to obtain the data from the state on the breakdown in cases between the vaccinated and unvaccinated.

Email notifications are only sent once a day, and only if there are new matching items.

Email notifications are only sent once a day, and only if there are new matching items.

Email notifications are only sent once a day, and only if there are new matching items.

Email notifications are only sent once a day, and only if there are new matching items.

Just in from the CDC - The document -- a slide presentation -- outlines unpublished data that shows fully vaccinated people might spread the Delta variant at the same rate as unvaccinated people.

Until more people get vaccinated, this is going to be our life," added Santella.

Had a huge picnic last week, going to a concert in a few weeks, going everywhere maskless.