Two new variants of the coronavirus are circulating in Connecticut, and local doctors say they're even more infectious than previous strains.

"BA.4 and [BA.]5 are rising in Connecticut. I mean right now we're still BA.212.1 mostly,” said Dr. Albert Shaw, professor of medicine at Yale School of Medicine.

Doctors at Yale Medicine say the two new variants have caused surging cases in South Africa and Europe thanks to slippery new mutations.

"Each of these variants have evolved mutations, most of the ones that I think people focus on are in portions of the spike protein,” he said.

Shaw is an infectious disease specialist with Yale Medicine. He says the newest forms of the COVID virus are better than previous variants at resisting the antibodies that prevent infection.

"It could prolong the tail of our little wave here. Too early to know whether it'll be a surge, I hope not,” said Shaw.

He says the variants don't seem as resistant to T-cells, the part of our immune response that fights the infection and prevents severe illness or death.

"That seems to be largely preserved with our current vaccines and boosters, even with the variants. So, I think that's a bit of good news,” he said.

Shaw says masking in public places is still probably a good idea, especially for those with compromised immune systems or pre-existing conditions.

"Diabetes or obesity or chronic lung disease - they are still at increased risk, and I think you still have to be cautious,” said Shaw.

He says even if you're young, healthy and vaccinated, so-called "long COVID" can cause chronic lung damage, heart palpitations or brain fog.  

"Never had anything that you'd think would be concerning in terms of severe disease but had disabling symptoms afterward,” Shaw said.

Last week, the Connecticut COVID Tracker reported the two new variants made up about 12% of the state's new COVID cases in June.