Twenty million. That was the number of Americans who were supposed to be vaccinated against COVID-19 by now. Instead, more than 5 million people have received a shot, and 17 million doses have been shipped to the states and other jurisdictions that are distributing them to hospitals, doctors and pharmacies. “There is a complete lack of federal leadership, and it’s just horrifying,” says Dr. Tom Frieden, a former director of the CDC. “We heard, ‘It’s our job as Operation Warp Speed to deliver vaccines to states. Then it’s their job from there.’ But that’s not how public health works in the U.S.”
As it is, state and local health departments are struggling to implement an unprecedented mass-vaccination program while also managing a surge in new COVID-19 cases—some 200,000 daily for many days in December and January—and record-breaking numbers of hospitalizations. Shrinking budgets have left some states scrambling to find the staff and expertise needed to stand up a complex system of receiving, storing, distributing, tracking and administering vaccine doses, not to mention educating the public about the shots and monitoring for side effects. “Early on, there was talk at the federal level that states don’t need money, they are like pass-throughs for this stuff; it’s going to be the health care systems that are going to do the vaccinating,” says Kris Ehresmann, director of infectious diseases at Minnesota’s department of health. “States and localities have a really, really big lift.”
Some of the shortfall may be a reporting lag as states learn new tracking systems, but there clearly are real problems. In Texas, data-entry issues led officials to overestimate the number of available doses, leaving unvaccinated many health care workers in the first group of eligible people who wanted the shot. Health officials in Lee County, Florida, decided to do without an online appointment system and offer limited vaccines on a first-come, first-served basis, which prompted elderly people to wait overnight, some up to seven hours, to get their shots.
The risk posed by the slow pace of the vaccination campaign is now amplified by new variants of SARS-CoV-2 that appear to spread more easily among people, which means a COVID-19 vaccine has never been more critical. First reported in the U.K. in December, the mutation in SARS-CoV-2 has since appeared in the U.S., while yet another, more worrisome variant of the virus—which may be better able to evade the immune defenses the body generates—has emerged in South Africa. With these new mutated versions of the virus, the pace and completeness of vaccinating the public becomes more crucial. The point of mass vaccination is to achieve herd immunity, in which the majority of the population is protected against COVID-19. For the virus, such a scenario is similar to a thief encountering a neighborhood of secured and alarmed homes: it’s harder to break in. The more quickly a fortress of immunity is built, the easier it is to thwart the virus as it hits blockade after blockade. If the vaccination effort is more piecemeal—as it is in the U.S. now with the plodding rollout—there may be more opportunities for SARS-CoV-2 to develop mutations that make it resistant to the vaccines. If that happens, those mutant variants can outcompete their cousins and dominate.
Some experts argue that even partial vaccine protection among a larger number of people is better than complete protection in a smaller group. They advocate for people getting their second shot about three months after the first (instead of the 21 or 28 days currently recommended). That way, more people could get vaccinated at least once and enjoy partial protection of slightly over 50% on average against COVID-19, according to some estimates, compared with the 95% provided by the current plan–and the virus’s spread would be slowed as well. It’s not perfect, but it could do more good for more people.
The U.K. adopted this strategy on Dec. 30—a controversial and, some health experts say, premature decision. There is no strong evidence for deferring the second dose, which the U.S. Food and Drug Administration (FDA) reiterated in a Jan. 4 statement supporting the existing dosing regimen. It’s also unclear whether the new SARS-CoV-2 variants cause worse disease and warrant such a change. So far, the antibodies and immune response generated by the vaccines can still neutralize the mutant viruses. Given how far the U.S. vaccination program has fallen short already, delaying the second dose, says Dr. Leana Wen, former health commissioner for Baltimore City, is “solving for the wrong problem. If we are unable to even administer the supplies of vaccine we have at the moment, what is the purpose of trying to increase the supply when we should be focused on increasing the rate of administration of the vaccine?” Frieden agrees: “We should be focusing on getting the vaccine out as rapidly, as widely and as equitably as possible.”
Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, says that may happen soon. “I think it’s premature to make a definitive statement about the rollout,” he says, noting that the holidays and the inevitable growing pains of launching a new, large-scale vaccination campaign have contributed to the low number of vaccinations to date. “I would give it another week or two to see if we catch up and gain momentum. If we do, I think we’re going to be O.K. If not, then I’ll say there is a problem here.” Fauci says U.S. researchers are studying the new variants to confirm how infectious they are, and whether current vaccines will continue to protect against them. But even if the new variants do end up escaping vaccine protection, he’s hopeful scientists will have a quick solution. The mRNA tech behind Pfizer-BioNTech’s and Moderna’s vaccines is designed to be flexible; it relies on inserting the right genetic sequences from the viral genome, so it should be relatively easy to swap out the existing sequence for one that addresses a new mutation. In the U.S., the modified shot would not have to go through the same months-long testing involving tens of thousands of participants and regulatory review that the original shot did. It would require only tests involving a few dozen people.
But even the most effective vaccine won’t save any lives if it doesn’t make it into people’s arms, and on that, the U.S. has a long way to go. As states move from high-priority groups like health care and frontline workers to the general public, they will face even bigger challenges in reaching people and addressing their questions and concerns about the vaccine. “If we want to make sure we are really reaching everyone who needs to be vaccinated, and not just people with good access to health care, that requires a lot of outreach and crafted, targeted opportunities for vaccinating people where they are comfortable,” says Ehresmann. “All of that targeted work requires effort and energy and, hence, more resources.”
This appears in the January 18, 2021 issue of TIME.