Some prioritization formulas also conflict with one another or mandate such regulations that they impede vaccinations, public health experts say. However, many Americans may not be aware of the algorithms that affect their access to vaccines.

Ellen P. Goodman, a professor at Rutgers Law School who studies how governments use automated decision-making systems, said algorithms are needed to efficiently assign the vaccines. However, public agencies and health centers should be transparent about the prioritization formulas, she added.

“We want to know who’s using them, what they’re trying to do, who owns the proprietary algorithms, and if they’re being audited,” she said.

The vaccine prioritization formulas can be roughly divided into three levels: federal, state, and local formulas. At the highest level, Operation Warp Speed ​​- a federal multiagency effort launched by the Trump administration – has managed the nationwide distribution of vaccines through Tiberius, an online portal developed by Palantir, the data mining giant . The Biden administration, which withdrew the name of the program, has taken over and continues the effort.

To split the doses, the federal administrators use a simple algorithm. It automatically splits the total amount of vaccines available each week across the 50 states plus US territories and some major cities like New York based on the number of people over 18 in each location.

However, some health officials and researchers described the Tiberius algorithm as a black box.

“Why can’t you publish the methods you use to make these estimates?” said Dr. Rebecca Weintraub, an assistant professor of medicine at Harvard Medical School, who co-authored a recent study of government vaccination schedules. “Why are states getting a different number of doses per week than expected?”

The states warned of the disadvantages of Tiberius last fall. In preliminary vaccination schedules submitted to the CDC, some state health officials complained that the platform was too cumbersome and that the algorithm’s weekly allocations made it difficult to plan month-long vaccination campaigns.