By CBSBoston.com Staff

BOSTON (CBS) – The number of communities in Massachusetts considered high risk for coronavirus infections has increased for the fourth week in a row. As of Thursday, the number of cities and towns in the high-risk red category is 77, up from 55 last week.

CHECK: Town By Town Coronavirus Data

State health officials categorize cities and towns as red, green, yellow or grey based on the daily rate of COVID-19 cases.

COVID cases by town 4/8/21 (Image credit Mass. DPH)

As of Thursday, the following communities are considered high risk:

Abington, Adams, Athol, Ayer, Barnstable, Billerica, Blackstone, Brewster, Brockton, Carver, Chatham, Chelmsford, Chicopee, Dennis, Dighton, Dracut, East Longmeadow, Edgartown, Everett, Fall River, Framingham, Freetown, Granby, Halifax, Hamilton, Hampden, Hanson, Holyoke, Hopedale, Hull, Lakeville, Lawrence, Littleton, Lowell, Ludlow, Lynn, Mansfield, Mashpee, Methuen, Middleboro, Milford, Monson, Nantucket, New Bedford, Oak Bluffs, Orange, Palmer, Paxton, Peabody, Plainville, Plymouth, Raynham, Rehoboth, Revere, Sandwich, Saugus, Seekonk, Somerset, Southampton, Southboro, Springfield, Sutton, Swansea, Taunton, Tisbury, Tyngsboro, Ware, Wareham, Wenham, West Boylston, West Bridgewater, West Springfield, Westport, Whitman, Williamstown, Winchendon, Yarmouth.

The red zone on this week’s map shows clear infection clusters, which is concerning to epidemiologists.

“We need to keep a very close eye on those clusters. Those red areas do worry me,” said Dr. Mark Siedner, an infectious disease specialist at Massachusetts General Hospital.

So far, five million shots have landed in Massachusetts and 1.6 million people are fully vaccinated.

“The concern I have is that hospitalizations are up 20% in the last two weeks. That shouldn’t be happening if high risk people are truly protected,” Dr. Siedner said.

While cases and hospitalizations are on the rise, death rates have stayed the same. Dr. Siedner says we’ll know in a couple more weeks if there’s cause for concern.

“I think you’re seeing the medical and epidemiological community holding its breath asking the question – have we opened up too fast? Or is vaccination catching up as fast as we need it to? And time will tell,” Dr. Siedner said.

Dr. Siedner said while the state reopens the economy, people should remember to limit their social interaction and continue to wear masks.

The Massachusetts Department of Public Health reported 1,938 new confirmed COVID cases and eight additional deaths in the state on Thursday.

CBSBoston.com Staff