Santa Clara County has stopped scheduling first-dose coronavirus vaccine appointments, pointing to a low and unpredictable supply of doses from the state as the reason.

The news comes as a number of Bay Area officials, including in Santa Clara County, push back at the way the state has handled vaccine distribution — from an equity program they argue disadvantages needy areas of the region to tapping giant insurer Blue Shield to help with the state’s vaccine program.

“Due to low vaccine supply from the state and the need to conserve inventory for second dose appointments, the County Health System stopped scheduling first dose appointments on Friday, March 5, except for a limited number of walk-in appointments in community-based locations,” the county said in a statement. “The county will resume scheduling first dose appointments immediately when the vaccine supply received from the state allows us to do so.”

On Wednesday, the county said it had notified “several thousand” Kaiser patients who had booked appointments through the county for March 11 through March 21 that they were being transferred back to Kaiser because of supply issues.

“The county is transferring Kaiser patients’ appointments to Kaiser because the state has assured Kaiser it will have sufficient vaccine for its members and its vaccine sites, while the county has received no such commitment for the uninsured and vulnerable populations we serve,” Santa Clara County said.

The patients are all under age 75, the county said, adding that Kaiser told the county it would prioritize scheduling appointments for these transfer patients.

Kaiser said in a statement that while “vaccine supply continues to be limited and unpredictable at times for all providers, including Kaiser Permanente, we are pleased to be able to provide vaccinations for those Kaiser Permanente members whose appointments were just cancelled by Santa Clara County due to the county’s lack of vaccine.”

“Over the next several days, we will be reaching out directly to these members to reschedule their appointments as soon as we can,” Kaiser said. “We will also continue to vaccinate community members as vaccine supply allows, regardless of their health plan, through our Kaiser Permanente medical centers and through the many vaccination sites we are supporting along with public and private health care organizations. We do not anticipate this situation will affect any vaccination appointments already scheduled in our facilities.”

County Executive Jeff Smith expressed frustration with the state Wednesday, saying, “We don’t know where the decisions are being made about the allocations. We’ve asked and it sounds like (the California Department of Public Health) is no longer involved in the allocation decisions — and the allocation decisions are being made by government ops and Blue Shield, so we don’t know how much the Blue Shield agreement influenced it, if at all.”

In a statement, the state’s public health department said, “Vaccine supply is constrained by overall manufacturing. The federal government has said that it expects supplies to increase meaningfully in April and May. We are working with Blue Shield to create a vaccination network that will be able to administer 4 million doses per week by the end of April.”

Vaccine supply has constricted across the state, in part because of a shortage of expected vaccine from Johnson & Johnson. Gov. Gavin Newsom said Wednesday that the state didn’t expect to get more doses of the vaccine in the immediate future, but hoped that overall vaccine supply would “really start to move next month and the month after that.”

The issues could be compounded on Monday, when the state has said vaccine eligibility will expand to Californians with certain disabilities and conditions.

“At this point, we’re anticipating that the allocation will be lower than we need, so we’ll have to reassess after we find out about our new allocation,” Smith said. “Because of limitations on doses, inventory, I should say, we have to limit the number of appointments in order to fit the inventory that we have, and we have requirements for second doses that we really can’t skip, so what it would mean if we got less vaccine is that we’d have to further constrain the appointments.”