Supporting Literature
The novel coronavirus disease 2019 (COVID-19) pandemic resulted in 3, 016,515 confirmed cases and 131,666 deaths in the United States by July 8th, 20201 and led to the devastation of hospital systems across America2. As evidence grew of surgical masks effectiveness in transmission prevention 3,4 , the Centers for Disease Control and Prevention (CDC) revised its recommendations, urging everyone excluding infants to wear a mask or face covering in public settings where social distancing measures are difficult to maintain5,6. Further, the CDC simultaneously recommended the use of full-face shields to cover homemade masks, however, available designs are obtrusive and can reasonably be presumed to reduce community and healthcare worker compliance rates.
Early and sustained debate on the validity of public mask use was guided by supply shortages rather than established mitigation practices7. When national leaders advised and pleaded with the public to conserve and donate PPE for healthcare workers8, this validated and reinforced public opinions that mask use does not significantly mitigate public spread. At one point, the Surgeon General of the United States vehemently argued, emphasis his own, “Seriously people- STOP BUYING MASKS! They are NOT effective in preventing general public from catching [COVID-19]…!”8 Other actions and inactions from some federal agents and healthcare leaders inappropriately helped shift mask use to a political issue, rather than a public health issue9. The leading US infectious disease specialist Anthony Fauci would eventually state, “Masks are not 100% protective. However, they certainly are better than not wearing a mask…So masks work.”10
The threats imposed by COVID-19 have not passed and as stay at home orders and other social distancing restrictions prematurely ease, the rates of COVID-19 infection have begun to exponentially resurge. In the first week of July 2020, Arizona and Florida had 20,989 and 54,797 new cases of COVID-19, respectively1. Additionally, in the midst of this worsening global pandemic, the death of George Floyd sparked outrage against unlawful police brutality towards communities of color. Americans have rightfully crowded streets to protest these moral and legal injustices11, despite the established role mass gatherings play in viral transmission of COVID-19. Further, COVID-19 has disproportionately affected communities of color12 due to established health care access disparities13,14 and lack of public outreach efforts15. These coinciding realities raise grave concerns and will almost certainly re-invigorate and require community efforts to generate accessible, affordable and comfortable personal protective equipment (PPE) for community and healthcare worker needs.
Reports on transmissibility of COVID-19 suggest up to 44% of cases may be due to transmission through asymptomatic patients16, which is identified as a major barrier to containment17. Current evidence establishes respiratory droplets as the major mode of COVID-19 transmission.18 The nose, eyes, and mouth are all potential sites of viral entry. Current Healthcare Infection Control Practices Advisory Committee (HICPAC) guidelines establish routine facial protection with face shield or goggles during all patient care for illnesses, such as severe acute respiratory syndrome (SARS) and avian influenza, which spread by respiratory aerosol droplets.19 Therefore, the production and distribution of efficient, durable, and inexpensive PPE has become of remarkable, unprecedented importance.
Face shield overcome some of the major limitations of standard masks. They provide superior face coverage, while remaining durable and reusable. In contrast to goggles, face shield may be superior, as they guard the entirety of the face from infectious respiratory droplets, but admittedly do lack a reasonable seal with the skin. A 2014 study showed that using a face shield resulted in a 96% reduction of inhalation exposure immediately after a cough.20 Full face shield also reduced surface contamination of a respirator by 97%. When a smaller cough aerosol was used (VMD = 3.4 μm), the face shield was less efficacious, reducing only 68% of inhalation exposure after a cough and 76% of respirator surface contamination. These findings indicate adjunctive use of face shields can effectively reduce short-term exposure to large and small aeroslized particles, however they cannot replace respiratory protection.20
Demand for PPE has already outpaced world commercial supplies.21 In response, the FDA stated it will not object to the distribution and use of improvised face shields that are intended to serve a medical purpose throughout the duration of the COVID-19 public health emergency.21 A number of homemade face shield models have already been published. One design secured to the forehead utilizes transparent sheets, hole punchers, string, and paper surgical tape.22 A separate design utilizes a transparency plastic slide, which is secured onto a cloth or disposable mask using sewing materials, hole puncher, and strings.23 Our similar design was first publicly available April 3, 2020 via publication in the Wall Street Journal24. Our design is advantageous, as the printable model guarantees a broad, accessible distribution model; print and assembly time are minimal (< 2 minutes); and materials are inexpensive and widely available.
Our societies cannot repeat past mistakes in their relationships with homemade PPE. Where hospital and community face shield use can be predicted to rise together in the coming weeks and months25, so can further supply constraints. The need for community resource generation has been established and will continue to be essential to viral mitigation. We can no longer wait for commercial industries to answer this call. There is an immediate need for community manufacture and distribution of PPE to health care workers and communities; with proper education and motivation, communities can be depended upon to help assist with this effort, as they showed with homemade masks26. Our face shield design is an imperfect, yet adequate solution that is simple, cost-effective, and available now.
2. Montgomery, Philip, and Jonathan Mahler. “Inside the Public Hospitals Trying to Save New York.” The New York Times, The New York Times, 15 Apr. 2020.
3. World Health Organization. Shortage of personal protective equipment endangers health workers. Bull World Health Organ. 2020. doi:10.2471/BLT.20.010420
4. Leung NHL, Chu DKW, Shiu EYC, et al. Respiratory virus shedding in exhaled breath and efficacy of face masks. Nat Med 2020. April 2020:1-5.
6. Centers for Disease Control and Prevention. Use Cloth Face Coverings to Help Slow Spread | CDC. CDC.
11. “George Floyd Death: More Large Protests in US but Violence Falls.” BBC News, BBC, 3 June 2020,
12. Garg S, Kim L, Whitaker M, et al. Hospitalization Rates and Characteristics of Patients Hospitalized with Laboratory-Confirmed Coronavirus Disease 2019 — COVID-NET, 14 States, March 1–30, 2020. MMWR Morb Mortal Wkly Rep. 2020;69(15):458-464. doi:10.15585/mmwr.mm6915e3
16. He X, Lau EHY, Wu P, et al. Temporal dynamics in viral shedding and transmissibility of COVID-19. Nat Med. 2020;26(5):672-675. doi:10.1038/s41591-020-0869-5
17. Kimball A, Hatfield KM, Arons M, et al. Asymptomatic and presymptomatic SARS-COV-2 infections in residents of a long-term care skilled nursing facility - King County, Washington, March 2020. Morb Mortal Wkly Rep. 2020:69:377-381. doi:10.15585/MMWR.MM6913E1
18. Zhang R, Li Y, Zhang AL, Wang Y, Molina MJ. Identifying airborne transmission as the dominant route for the spread of COVID-19. Proc Natl Acad Sci. June 2020:202009637. doi:10.1073/pnas.2009637117
19. Siegel JD, Rhinehart E, Jackson M, Chiarello L. 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Health Care Settings. Am J Infect Control. 2007;35:S65-164. doi:10.1016/j.ajic.2007.10.007
20. Lindsley WG, Noti JD, Blachere FM, Szalajda J V., Beezhold DH. Efficacy of face shield against cough aerosol droplets from a cough simulator. J Occup Environ Hyg. 2014;11(8):509-518. doi:10.1080/15459624.2013.877591
21. Gupta S, Jangra RS, Gupta S, Gujrathi A V., Sharma A. Makeshift face shield for healthcare professionals during the COVID-19 pandemic. Clin Exp Dermatol. 2020. doi:10.1111/ced.14252
22. Ino Y, Yano T, Yamamoto H. A new simple method of handmade face shield using A4‐size OHP sheet, during the COVID‐19 pandemic. Dig Endosc. 2020;1-5. doi:10.1111/den.13724
23. Khan MM, Parab SR. Simple Economical Solution for Personal Protection Equipment (Face Mask/Shield) for Health Care Staff During COVID 19. Indian J Otolaryngol Head Neck Surg. 2020. doi:10.1007/s12070-020-01863-4
25. “Face Coverings on!” Oregon and the Workplace, Oregon Health and Science University, 30 June 2020,