In the early stage of the COVID-19 pandemic, hospitals in New York City struggled mightily to cope with an epic surge of coronavirus patients. Across the country, the pandemic has strained supply chains for critically important materials and equipment such as personal protective equipment and ventilators.

During the next two months, vaccine makers hope to recruit 60,000 Americans to roll up their sleeves to test the two vaccines, one made by Pfizer and BioNTech, a German company, and the other by biotech startup Moderna. While small tests earlier this year showed the preventives were safe and led to participants developing antibodies against the virus, the final phase 3 testing is designed to prove whether the vaccine reduces the risk of infection.

The study findings follow other research showing that minority healthcare workers are likely to care for minority patients in their own communities, often in facilities with fewer resources. Those workers may also see a higher share of sick patients, as federal data shows minority patients were disproportionately testing positive and being hospitalized with the virus, said Dr. Utibe Essien, a physician and core investigator for the Center for Health Equity Research and Promotion in the VA Pittsburgh Healthcare System.

Respiratory therapists have been in short supply during the COVID-19 pandemic. A study published in 2015 identified the supply of ventilators and the staff to manage them as a weak point in the U.S. healthcare sector’s capability to function effectively during a public health crisis.

The COVID-19 pandemic poses the greatest public health threat in the United States since the Spanish flu outbreak a century ago. As of Aug. 4, more than 4.8 million Americans had been infected with the novel coronavirus and 159,000 had died, according to worldometer.