Traditional manufacturing concentrates capacity into a few discrete locations while applying lean and just-in-time philosophies to maximize profit during times of somewhat predictable supply and demand. This approach exposed nationwide vulnerabilities even during local crises, such as the United States saline shortages following closure of a single plant in Puerto Rico following Hurricane Maria in 2017.1 Interruptions to the supply chain due to pandemic plant closure, weather, politics, or surge demand can cause immediate and lasting shortages. Nasal swabs were a clear example.
At the onset of COVID-19, 2 companies—Puritan in Guilford, Maine, and Copan in Italy—manufactured nearly all of the highly specialized nasopharyngeal (NP) swabs singled out by the Centers for Disease Control and Prevention (CDC) and the US Food and Drug Administration (FDA) to test patients for COVID-19. Demand for swabs skyrocketed as the virus spread, and they became unattainable. The lack of swabs meant patients went undiagnosed. Without knowing who was positive, people with symptoms and known contacts were presumed positive and quarantined, impacting isolated patients, the health care professionals treating them, and the entire US economy.
3-Dimensional Printing Solutions
Manufacturing NP swabs is not trivial. Their simple shape conceals complexity and requires highly specialized equipment. The lead time for one non-US machine manufacturer was > 6 months at the start of the pandemic.
Digital manufacturing/3-dimensional (3D) printing represented a potential solution to the supply chain crisis.2 Designers created digital blueprints for 3D-printed goods, face masks, face shields, and ventilator splitters were rapidly created and shared.3,4 Scrambling to fill the critical need for NP swabs, many hospitals, businesses, and academic centers began 3D printing swabs. This effort was spearheaded by University of South Florida (USF) and Northwell Health researchers and clinicians, who designed and tested a 3D-printed NP swab from photocurable resin that was printable on 2 models of Formlabs printers.5 Several other 3D-printed NP swab designs soon followed. This innovation and problem-solving renaissance faced several challenges well known to traditional manufacturers of regulated products but novel to newcomers.
The first challlenge was that these NP swabs predate FDA oversight of medical device development and manufacturing and no testing standards existed. Designers began casting prototypes out without guidance about the critical features and clinical functions required. Many of these designs did not have a clinical evaluation pathway to test safety and efficacy.
The second challlenge was that these swabs were being produced by facilities not registered with the FDA. This raised concerns about the quality of unlisted medical products developed and manufactured at novel facilities.
The third challenge was that small-scale novel approaches may offset local shortages but could not address national needs. The self-organized infrastructure for this crisis was ad hoc, local, and lacked coordinated federal support. This led to rolling shortages of these materials for years.
Two studies were performed early in the pandemic. The first study evaluated 4 prototypes of different manufacturer designs, finding excellent concordance among them and their control swab.6 A second study demonstrated the USF swab to be noninferior to the standard of care.7 Both studies acknowledged and addressed the first challenge for their designs.