The Centers for Disease Control and Prevention is warning Friday that the delta variant can cause more severe illness than earlier variants and spreads as easily as chickenpox.

Health officials are sounding the alarm after the CDC released the report.

"It's much more contagious than the common cold. It's about as contagious as chickenpox, which is a very contagious virus," says Dr. Jonathon Reiner, a professor of Medicine and Surgery at George Washington University.

According to the CDC document, vaccinated people as well as unvaccinated people can spread the virus. The new finding resulted in the new guidance on masking up regardless of vaccination status.

Health officials say unvaccinated people face much harsher consequences if they catch the variant.

"We are encouraging anyone who is not vaccinated to get vaccinated," says Carolyn Gulotta, a nurse at St. Francis Hospital. "It's the only way to protect yourself from this variant."

That's why people like Oyster Bay resident Peter Clark got vaccinated at a pop-up location at St. Edward in Syosset on Friday.

"I've just been hesitant from all the conflicting reports, but I finally made up my mind that it's the right thing to do," Clark says. "...Having a mobile vaccine right here makes it so easy to just get it done."

Another pop-up clinic will be held Saturday at St. Elizabeth of Hungary Church in Melville. There's also one at St. Dominic's in Oyster Bay on Sunday.

Click here to find a testing site.