The Grants Pass Clinic in southern Oregon is more than ready to administer the COVID-19 vaccine to its 20,000-some patients. It has seven exam rooms devoted to vaccination. The staff has ordered fridges and syringes. The phones ring nonstop, with patients calling to ask when they can come in to get their shot. But the clinic has barely any doses to give out.

Christi Siedlecki, the CEO of the clinic, has tried to get them. She registered her clinic’s interest in providing vaccinations with the state, and the state told her she was approved. But still: no vaccine. She asked the local health department for some doses. They gave her 30. “Obviously, that won’t get us far, but at least it’s something,” she told me recently. The only reason she’s getting them, she suspects, is because of “all the begging and bugging I do every day.”

Most primary-care doctors haven’t received doses of the COVID-19 vaccine to dispense to their patients, according to two different trade groups for small-practice doctors. (Federally Qualified Health Centers, which get federal funding to provide care in underserved areas, have had better luck, and are part of the Biden administration’s vaccination plan.) Like Siedlecki, many primary-care doctors are begging their local and state health departments for doses, but mostly without success.

Primary-care doctors see themselves as ideal foot soldiers in the battle to vaccinate America. After all, they know the extent of their patients’ preexisting conditions, are accustomed to soothing fears about vaccines, and can reach elderly patients quickly for an appointment. In Pennsylvania, a family doctor named Kevin Wong told me he has a 100-year-old patient who won’t leave his house. If he had the vaccine, Wong would be willing to make a house call.

That would be a smoother experience than the one many seniors have had as they’ve sought vaccination in recent weeks. Some people are walking into their local health department to ask for the vaccine, only to be turned away and told to call an overwhelmed phone line. “I have been calling my doctor, my hospital, my insurance, and the Health Department since the beginning of December to get a COVID-19 vaccination,” a Floridian named William Klein wrote to his local paper. “No one had any information.” A 75-year-old named Betty told a Los Angeles Times reporter recently that though she would like to get the vaccine, “I have no idea where.” Another Florida man said he had to click 800 times to enter his date of birth on a cantankerous county website.

“The most vulnerable populations, just like the ones that are most affected by COVID, are not necessarily the ones that are going to be able to scour the internet to find a place to go,” says Anders Gilberg, senior vice president at the Medical Group Management Association, which represents doctors in private practice. Many people already get their flu vaccine at their primary-care doctor’s office. So why not the COVID-19 vaccine?

The reason, in short, is that there is simply not enough of the vaccine to go around. Seniors might be frustrated, but so are local and state health departments, governors, doctors, and pretty much everyone else I’ve called in the past week. They’re all saying the same thing: They wish they could get more doses of the vaccine—especially the Moderna version, which does not have to be kept at ultra-low temperatures. They also want it sent to them by the federal government on a more predictable schedule. The Biden administration might help with both of these problems, but so far, it has been a long and bitter month of waiting.

“We desperately want to put vaccines in the hands of providers. But we can’t give them vaccines until we receive them,” says Michael Weber, who runs the health department in the county where Siedlecki’s clinic is located. Before last week, the health department had received a total of just 300 doses of the vaccine.

Let’s back up to the halcyon days of December, when it was thought that there was a chance—a chance!—that vaccination would go smoothly. The first doses of the vaccine went mostly to hospitals, in part so they could vaccinate their own employees, and in part because hospitals had the ultra-cold storage the Pfizer/BioNTech vaccine requires. It’s also faster to deliver 100 doses of vaccine to one hospital than a few doses of vaccine to 100 doctor’s offices.

In addition to hospitals, states sent the vaccine to county health departments because, the thinking was, health departments could get doses into arms quickly. Health departments “know how to do mass-vaccination clinics,” Marcus Plescia, the chief medical officer at the Association of State and Territorial Health Officials, says. They know how to set up a big tent with metal chairs and vaccinate hundreds of people within a few hours. Getting the vaccine to other types of doctors and pharmacies, as I heard over and over in recent days, is impossible until there’s more of it.

This shortage of doses is why, in Palm Beach County, Florida, 100,000 seniors were on a waiting list recently for only 4,000 doses of vaccine. In Louisville, Kentucky, 40,000 people have signed up to wait for their dose. Walton County, Florida, opted against even maintaining a waiting list, because it was taking too long to call everyone back to schedule an appointment.

These waiting lists might seem strange, given that states supposedly haven’t administered all of the vaccine they’ve been allocated. As of this writing, for example, North Dakota is performing the best, having used 74 percent of the doses it’s received. If states have extra vaccine sitting around, why not give it to Siedlecki or Wong or another doctor to give to some of those patiently waiting seniors?

Because those doses, which exist but haven’t been used yet, “are spoken for—they’re gone,” Claire Hannan, executive director of the Association of Immunization Managers, told me. Some are in hospitals, and some are reserved for long-term-care facilities, where CVS and Walgreens are vaccinating residents as part of a federal program. It’s taking the pharmacy chains some time to get through these facilities, making it appear as though there’s a big pile of vaccines sitting there, just waiting to be injected. (Plescia thinks the distribution numbers aren’t accurate, and that state data systems might not be showing the latest immunization figures.) Those numbers look bad for states, which makes health directors less eager to send precious vaccines to a bunch of small-practice doctors, only to risk having more doses of vaccine sit around unused.

When the Trump administration earlier this month urged states to begin vaccinating people older than 65 and those with underlying conditions, the public-health world erupted in quiet panic. The federal government hasn’t sent them enough vaccine to cover everyone over 65, and some states haven’t yet finished vaccinating health-care workers—the first-priority group. Health directors are saying that deliveries of the vaccine have been small and unreliable. The problem, they say again, is the supply.

Both Moderna and Pfizer are trying to increase vaccine production, according to a White House coronavirus adviser who would only speak to me on the condition of anonymity. But because the technology to make the vaccine is so specific, it doesn’t make sense for the government to build a new factory for manufacturing it, the adviser said. In the time it would take to build a new facility to make the vaccine, the companies could expand their own production lines—something they’re already doing. The best hope for quickly expanding vaccine supply lies with Johnson & Johnson’s vaccine, which should be ready soon.

The Biden administration might use the Defense Production Act to increase the production of medical supplies like syringes and needles that health workers need to administer the vaccine. It also plans to treat the pandemic like a natural disaster, giving states money and operational support through FEMA to help get vaccines into arms.

But even if the new administration achieves that, it might not make vaccination angst-free for at least a few more months. Hannan, with the Association of Immunization Managers, predicts that it might be April or May before people will be able to receive the COVID-19 vaccine in the comfort of their doctor’s office. The White House adviser I interviewed said it might be even later on, after the country has already reached herd immunity.

But eventually, the vaccine will have to flow through doctors’ offices. Doctors are, after all, still the core of American health care. Some seniors are willing to battle through an 800-click website to get themselves immunized, but not everyone is. As Shawn Martin, CEO of the American Academy of Family Physicians, told me, if primary-care doctors aren’t eventually able to administer the vaccine, “I don’t think we’ll ever vaccinate 300 million people.”