Thousands of COVID-19 vaccination appointments are being canceled or not made at all because of limited supplies in the islands.

Maui Memorial Medical Center canceled about 5,000 first-dose appointments this week and has had to hold more than 15,000 requests due to lack of vaccine supply, a spokeswoman for hospital operator Maui Health told the Honolulu Star-Advertiser.

Meanwhile, Hawaii Pacific Health, which opened Hawaii’s first mass vaccination clinic Monday at Pier 2, will run out of vaccines after Jan. 27. It had filled nearly all of its appointments — 12,247 — with just 41 slots left as of Tuesday.

The Queen’s Medical Center, which is opening a large-scale immunization clinic Monday at the Blaisdell Concert Hall, had scheduled more than 5,500 appointments as of noon Tuesday since opening up registration the day before. Queen’s expects to have about 12,000 doses initially available for the clinic.

“At this point we just don’t have the vaccine that we thought we were going to be receiving or that we would like to be receiving,” Health Director Libby Char said Tuesday at a news conference. The state was expecting about 32,700 doses this week, down from nearly 59,000 last week. “We have a very limited supply. If we received an unlimited supply, we could probably triple or quadruple that and administer it in any given week, but we’re constrained by what we’re receiving from Operation Warp Speed and our federal partners.”

More than 70,000 residents have received at least one dose of the COVID-19 vaccine since December, but officials are warning the public that the future pace of vaccinations is uncertain.

States are constrained by the number of doses they receive from the federal government, which is basing allocations on population size, Char said.

That means Hawaii cannot plan ahead to ensure enough vaccines will be available at this point. The state is currently immunizing health care workers, long-term care facility residents, adults 75 years and older and front-line essential workers. It hopes to begin vaccinating in the spring adults between 65 and 74 years, those 16 to 64 with high-risk medical conditions and other essential workers. By the summer the plan is to roll out vaccinations for the rest of the population — residents 16 years and older.

Hawaii has received 10,887 doses per 100,000 residents, or 154,150 total to date, according to the Centers for Disease Control and Prevention.

“One of the concerns is because we’re opening up the so-called public mass vaccination pods … we just want to manage the public’s expectation because we haven’t had an increase in the vaccine supplies from the federal government,” said DOH spokeswoman Janice Okubo. “It’s unpredictable because it’s really at the federal government, which just tells us how much we’re going to get. Not knowing what it’s going to be from week to week, it is challenging to plan these larger pods.”

Hawaii reported two new coronavirus-related deaths on Oahu and 65 new infections statewide, bringing the state’s totals since the start of the pandemic to 324 fatalities and 24,546 cases. The U.S. COVID-19 death toll surpassed 400,000 on Tuesday, with total infections across the nation topping 24 million.

“We have a high demand here. Many people want the vaccine, but right now the demand is outpacing the supply,” Okubo said. “We don’t want there to be cancellations and rescheduling, but it’s incumbent on those hospital systems to make those appointments carefully because we can’t just assume we’re going to get a certain amount of vaccine, because we haven’t been getting it.”

Hawaii is aiming to immunize the following priority groups in the first phase of the vaccination plan:

>> Phase 1-A: 60,000 (50,000 health care workers, 10,000 kupuna in care homes)

>> Phase 2-B: 159,000 (109,000 kupuna 75 and older, 50,000 front-line workers)

>> Phase 1-C: 148,000 individuals 65 and older