BOSTON (WWLP) – Massachusetts is a national leader in vaccine distribution, but parts of western Massachusetts still fall short of the state’s goal.

Earlier this week, the state hit a major milestone in vaccinating more than 4.1 million residents, but Hampden County currently has the lowest vaccination rate in the state with just 52 percent of adults having their first dose.

According to the Department of Public Health, Massachusetts achieved herd immunity once 4.1 million residents were fully vaccinated. The concern of state health officials now is the two counties in the state where less than 60 percent of the population has received a vaccine.

In Bristol County, which includes the cities of Fall River, New Bedford, and Taunton just 54 percent of residents are vaccinated. Followed by Hampden County where just 52 percent of residents have received the vaccine.

“Well, obviously we continue to chase opportunities to vaccinate people in many of the places where we still have a lot of room to make up to get to where we are overall across the state,” Baker said on Wednesday.

Over the next few weeks, the Baker Administration plans to set up more pop-up clinics in Bristol and Hampden County. The clinics aim to bring vaccines right to people’s doors and provide information about how safe it is to get vaccinated.