The U.S. COVID-19 Vaccine Rollout Is Getting Faster. But Is It Enough?

On Dec. 8, 2020, when then-President Elect Joe Biden promised that his incoming administration would deliver 100 million doses of COVID-19 vaccine to patients’ arms in his first 100 days in office, none of the highly anticipated inoculations were yet authorized. Even with highly promising results from medical trials and months of planning by state and federal authorities for the rollout, it is not a safe bet to hinge grand political ambitions on a cat’s cradle of government bureaucracies.

While the U.S. Food and Drug Administration issued an emergency use authorization for the Pfizer-BioNTech vaccine three days later (and another for Moderna’s shot on Dec. 18), the first several weeks of the rollout were ridden with missteps and crossed wires as doses piled up in overstocked long-term care facilities, and in some cases the trash (though there is scant data on the number of wasted treatments). In the 38 days between the first vaccinations on Dec. 14, and when Biden took office on Jan. 20, the federal government had shipped 42 million doses. But less than half—16.5 million shots—were administered. Since then, the pace as picked up considerably, according to historical data compiled by TIME.

Since Biden took office, the pace has picked up considerably. Of the 68.3 million total doses that have arrived on site as of this week (according to CDC figures collected by reports from states and jurisdictions) some 46.3 million—over two-thirds—have reached patients. Another way to look at it: in the 23 days between Biden’s first day in office and Feb. 11, the U.S. administered just shy of 30 million doses. This comes to an average of 1.3 million a day, nearly three times the rate in the final five weeks of Trump’s term. By simple extrapolation, this figure would suggest that the U.S. will easily surpass 100 million new inoculations in the 77 remaining days in Biden’s self-imposed deadline.

As you can see in our chart above, since late January, doses administered per week—the blue line, which is a rolling sum of the previous seven days—has surpassed the number of doses that the U.S. Department of Health and Human Services allocates each week—the tall yellow bars. There’s a problem, however: despite the increasing pace, there remains an apparent surplus of more than 20 million doses already shipped and still available. At the same time, conversely, there are widespread reports of hospitals and other facilities cancelling appointments due to a shortage of supply as they are flooded with a much larger number of eligible Americans than initially expected at this stage in the rollout.

So where is this surplus, and why isn’t it reaching patients? The short answer is that in many cases we don’t know–a “we” that includes not only the public but the many overlapping authorities in charge of the vaccine distribution. As the Kaiser Health News recently put it, “Many states don’t know exactly where the doses are, and the feds don’t either.”

There are several possible explanations. The worst is that a great number of these unused vaccines have been discarded, given that they can quickly spoil after they’re removed from cold storage. While there are numerous reports of this happening, the data are circumstantial, given that states regularly fail to report doses they throw out, as ProPublica recently reported. A more plausible scenario is that, given how rapidly states have shuffled their vaccine eligibility rules, many thousands or millions of unused doses are at the wrong facility—say, at elder care centers where allotments initially overestimated the required supply. In South Carolina, for example, the state health department recently announced that it would redistribute 37,800 unused doses originally intended for longterm care facilities to providers who can get the vaccines to other eligible individuals who have struggled to get appointments.

This is easier said that done, particularly since both vaccines require two doses, ideally three or four weeks apart, meaning some unused vaccines might be earmarked for those awaiting their second shot, or held in anticipation of a forthcoming stage of the rollout or anticipated change in eligibility requirements. It’s a logistical nightmare: States must locate and track unused vaccines, determine if they are planned for future distribution or merely idling in cold storage, and, if so, decide which providers need them the most.

Moving forward, the most critical issue will be whether the vaccine supply will fall short of demand as the distribution process becomes more efficient. Many have warned that shortages could grow more dire for several months given there’s only been so many shots actually manufactured. There are signs that both Pfizer and Moderna will be able to boost their production by the spring—though at that point, tens or hundreds of millions more individuals will become eligible in the U.S. In the interim, the most telling indicator of the supply-demand balance will be whether the number of vaccines administered each week continue to outpace shipments. Every week that more vaccines are administered than are shipped will cut further into whatever surplus is still available, increasing the risk that states simply run dry on doses.

Acknowledgements

These figures are extracted from the U.S. Centers for Disease Control and Prevention’s vaccination tracker, which publishes only the latest cumulative numbers, not figures over time. TIME logs the status of the dashboard every 30 minutes to preserve the historical data. These data were collected with the CDC’s blessing and the essential services of the Internet Archive’s Wayback Machine, which was able to close several caesurae resulting from this reporter accidentally closing his laptop. Where there were brief gaps in the data early in the rollout, figures were interpolated based on a simple linear regression.