(WGHP) – A new form of the COVID delta variant has been found in Massachusetts and seven other states, according to CBS News. It has been named AY.4.2, but is also referred to as “delta plus.”

Besides Massachusetts, the variation has been found in labs in the following states:

Health officials in the District of Columbia have also reported at least one case of AY.4.2.

The new strain is being investigated by health officials in the U.K. who say they have seen a growing amount of cases. A small fraction of COVID cases in the U.S. over the last several weeks have been linked to delta plus, and American health officials are working to study it.

“We have teams that are constantly reviewing the genetic sequence data and looking for blips, an increase in a certain proportion, or just something that’s completely new,” said Dr. Summer Galloway, executive secretary of the U.S. government’s SARS-CoV-2 Interagency Group.

Delta plus does not cause more severe illness, and current vaccines are effective against it. It is similar to the existing delta variant, except that it has a spike protein mutation called the K417N. Spike proteins are external bumps the virus uses to hook onto human cells. The delta plus mutation is the same one previously identified on the beta variant. According to the Washington Post, some experts believe delta plus could be even more contagious than the now dominant delta variant, but there is no widespread consensus on that conclusion at this point.