A widespread shortage of health care workers who can get COVID-19 booster shots into the arms of Oregonians could lead to a months-long delay before every eligible resident will be able to get one, the Oregon Health Authority said Friday.

Unless the state is able to speed up the current pace, it could be March before the state meets demand.

“Hospitals are still at capacity in many parts of the state, pharmacies are busy with multiple workstreams, and clinics have large numbers of patients who have delayed needed care and are now needing their time,” Oregon Health Authority spokesperson Erica Heartquist said in an email Friday.

Officials say the pandemic’s toll, especially the latest record summer and fall surge, has overwhelmed the health care system and exhausted many health care workers, causing some to quit.

Heartquist said limited supply also is a contributing factor to Oregon’s slow rollout of boosters, with “isolated instances” of vaccination clinics in the state running out of vaccine and having to wait up to a few days to get more. Heartquist said Oregon is asking for its full per capita allotments of vaccine, and then some on top of that.

The bottlenecks couldn’t come at a worse time: Demand has been soaring among fully vaccinated Oregonians who are heeding warnings over waning immunity and the onslaught that omicron might bring.

Several preliminary studies released earlier this week show the omicron variant appears to significantly reduce the effectiveness of two shots of Pfizer-BioNTech vaccine, but a booster shot can markedly improve the body’s defenses. Dr. Anthony Fauci, the federal government’s top infectious disease expert, also said this week that it’s only a question of “when, not if” the definition of fully vaccinated changes to include a booster.

Oregon isn’t the only state seeing intense demand. Many others are struggling, too. Oregon officials point out that, according to the Centers for Disease Control and Prevention, about 30% of fully vaccinated residents in Oregon have received an extra dose, compared to 26% nationally.

Like Oregon, many states haven’t been able to rapidly accelerate their vaccination efforts.

Oregon officials describe a dramatically different landscape than that of the earlier days of the state’s vaccination rollout, when thousands were getting their first and second shots each day at mass vaccination sites that included Portland International Airport, the Oregon Convention Center and the state fairgrounds in Salem. At its peak in April, the state was getting shots into the arms of 50,000 people each day.

Today, smaller vaccination sites across the state are administering about 24,000 shots per day, with about 15,000 of them booster shots or third doses.

Approximately 830,000 residents already have received their extra shot. But at the rate of 15,000 per day, it’ll take 80 more days – or until the end of February – to get extra shots into the arms of about 1.2 million residents who are currently eligible because it has been at least two months since their first Johnson & Johnson shots or six months since their second shots of Pfizer-BioNTech or Moderna vaccines.

From now until February, however, about 300,000 more residents will have become eligible, stretching the date into March when everyone who’s eligible for an extra shot can get one, according to state estimates.

However, It’s unclear if everyone who is eligible for boosters will want one. A Kaiser Family Foundation survey found that about 80% of fully vaccinated Americans would “definitely” or “probably” get or have already gotten their booster shots. Close to 20% said they “probably” or “definitely” wouldn’t get a booster. But that poll was taken in the two weeks before Thanksgiving, prior to news of the omicron variant.

Even if just 80% of Oregon’s fully vaccinated population decides to get a shot, at the current rate of 15,000 shots per day, it’d still be the end of February before everyone got their extra dose. But it could be earlier if the state is able to increase its capacity to administer vaccines.

By the end of February, however, it might be time for yet another shot if scientists decide that retooled vaccines are necessary to better defend against omicron’s many mutations. Pfizer-BioNTech and Moderna are both planning for that possibility. Retooled vaccines could be ready as soon as March, both companies have said.

Public health experts say even if another, retooled shot is necessary, it’s important not to delay getting a booster. Omicron had been detected in 25 states as of Friday, including Washington but not Oregon. Officials say it’s already likely in Oregon, and it has the potential to spread rapidly and widely.

For now, Oregon officials are trying to increase their capacity to administer the current vaccines – focusing in particular on higher risk populations, such as residents of nursing homes and other long-term care facilities.

Oregon Department of Corrections spokesperson Jennifer Black said state prison officials have offered an extra dose to any fully vaccinated inmate who wants one. So far, about 47% of inmates have received a booster or extra dose.

Outside prison walls, five high-volume, walk-in vaccination sites are up and running – in Beaverton, Gresham, Salem, Redmond and Central Point in Jackson County, with plans to stay in operation through at least the end of January. Officials also plan to open additional high-volume sites in Springfield next week and Wilsonville by the end of the month, plus more sites in the new year. The sites are offering boosters, as well as first and second shots.

Lines at the high-volume vaccination sites have ranged from non-existent to some that take two hours to clear. One Portland resident who was vaccinated Friday at Tektronix told The Oregonian/OregonLive that, thanks to “really efficient” organization, it took only 17 minutes to get to the front of a line that was a few hundred people long.

Check out the current list of high-volume sites here or visit getvaccinated.oregon.gov to find additional locations, such as at pharmacies and medical offices. But some pharmacies and medical offices are still showing no appointments available, which has frequently been the case for the past few weeks.

“Access to vaccine booster doses is challenging right now, but is improving,” said Heartquist, the Oregon Health Authority spokeswoman. “We ask people for some patience.”

— Aimee Green; agreen@oregonian.com; @o_aimee