The first of six planned state-run mass vaccination sites are opening Friday at the Baltimore Convention Center Field Hospital and Six Flags America in Prince George’s County.

Due to limited supply, however, vaccinations are by appointment only. 

State health officials are hoping the sites will lead to a more efficient distribution process. 

“Mass vaccination sites are a critical element in the statewide network of vaccination options that we are establishing,” Dennis Schrader, the acting state health secretary, said in a statement. “These sites will promote equitable access to vaccines by supplementing the sites operated by local health departments, hospitals, pharmacies, and other local partners.”

But some local health officials, like Carroll County Health Officer Ed Singer, are skeptical. 

“We're just concerned with it being supply limited right now, that it’s not the right time to be expanding the sites,” he said. 

Singer spoke at a recent vaccine briefing with lawmakers and state health officials, questioning how accessible those sites could be for elderly residents. 

“Each additional location, whether it's a pharmacy or mass vaccination site that the state gives doses to, reduces the number of doses that local health departments have available to reach our most vulnerable populations,” he said. 

A third site at M&T Bank Stadium is to open in mid-February. The state health department has yet to finalize the other locations. 

Eligible residents can register for a vaccine appointment at the Baltimore Convention Center via www.umms.org/BCCvaccine. Residents who need assistance registering can call 410-328-9865 from 9 a.m. to 4:30 p.m. from Monday through Friday.