The study’s damning conclusion: “The evidence suggests that ineffective national policies and responses, especially as compared to those of other wealthy nations or compared to the intricate preparation and planning by previous administrations of both parties, have been driving the terrible toll of COVID-19 and its inequities in the U.S.”

The costliest errors were committed in the pandemic’s earliest stages, the study finds. The Trump administration’s initial U.S. travel ban on Jan. 31 applied only to non-U.S. travelers and only to travelers coming from China, though the virus was “already known to be present in Italy, Iran, Spain, Germany, Finland, and the United Kingdom.” No symptom screening on arrival was required, nor was quarantining. Later research “found repeatedly” that “the great majority” of the virus introductions to the U.S. came not from China but from European strains.

The U.S. imposed restrictions on travel from Europe in mid-March, but by then it was too late. The virus had already spread so widely in the U.S. that when it arrived in a new state or region, it most likely came from elsewhere in the country. “This shows that any action to prevent introductions would need to be at the national level,” the study finds, “and while the window for effective action was brief, it was missed.”

Several other countries handled the pandemic far more effectively. For example, Australia closed its borders to all non-Australian citizens on March 15, when only 300 cases had been reported, and mandated “14-day, supervised quarantine in a hotel for all international arrivals (including Australian citizens)” plus “aggressive testing and contact tracing.” As of Nov. 12, Australia had recorded 36 COVID-19 deaths per million vs. 773 COVID-19 deaths per million in the U.S., says the Johns Hopkins Coronavirus Resource Center. “This is the difference between establishing effective national border policies and failing to do so,” the researchers say.

Those blunders can’t be corrected, but others can be. The study identifies three workplace policy mistakes that could still be remedied at any time.

Failure to use federal authority and budget to supply PPE. Eight months into the pandemic, over 80% of U.S. nurses report they are still reusing at least one type of single-use PPE, says a recent survey by National Nurses United, the country’s largest registered nurses’ labor union. From the pandemic’s beginning, the Harvard study finds, “supplying PPE was delegated to a variety of actors: state and city governments, large hospital chains, and in some cases small networks of clinics.” Washington could have used its spending power and its authority under the Defense Production Act to secure adequate supplies, if not immediately, then certainly by now.

Failure to require “mandatory universal paid sick leave for those unable to work due to COVID-19.” The Families First Coronavirus Response Act provides for some COVID-related leave, including family and medical leave, but it does not cover most federal employees or apply to employers with more than 500 employees.

Failure to mandate “standards for occupational exposures.” Such standards turn out to be extremely important: The researchers discovered that the volume of worker complaints to the Occupational Safety and Health Administration raising concerns about workplace conditions and exposure to COVID-19 are an excellent predictor of COVID-19 deaths 16 days later. Several states, but not all, have mandated such standards. For example, in July, Virginia issued rules on distancing, face coverings, cleaning, and other factors affecting employee exposure to the virus.

Though the study is discouraging, the researchers find reason for hope: “Despite the understandable dismay at the state of the pandemic in the United States, it is not too late to make a difference, and that difference starts with the implementation of apt policies.”