HARTFORD, Conn. (AP) — Some of the largest COVID-19 vaccination sites in Connecticut are shutting down as demand weakens and officials shift the campaign’s emphasis to mobile clinics, primary care offices and other smaller locations statewide.

The sites that provided their last jabs this week include one at the Pratt & Whitney airstrip in East Hartford and the Connecticut Convention Center in Hartford. Other mass vaccination sites have closed in Fairfield and Bridgeport.

“We knew this day would be coming, that we would not need these large sites to vaccinate folks,” said Dr. Jim Cardon, chief clinical integration officer for Hartford HealthCare, which operated the clinic at the convention center. “That doesn’t mean our work is done.”

With more than two-thirds of Connecticut residents having received at least one dose of the vaccine, demand for the shots has dropped significantly. The convention center, for one, was recently issuing less than 100 shots a day, down from as many as 1,200 doses a day. Connecticut’s major vaccine providers all plan to continue offering them at smaller sites.

The mass vaccination sites that have closed include one at Floyd Little Athletic Center in New Haven, operated by Yale New Haven Health.

“What we have seen is a real drop-off in the demand for vaccination,” Dr. Tom Balcezak, Yale New Haven’s chief medical officer, told the Hartford Courant. “We just don’t have the demand, unfortunately, to keep our large sites open.”