Perspective Open Access

Pulsed Ultraviolet C as a Potential Treatment for COVID-19

Fibrosis. 2023, 1(1), 10002;
Elroei David 1, *    Alina Karabchevsky 2,    Marina Wolfson 3,    Vadim E. Fraifeld 3, *   
Nuclear Research Center Negev (NRCN), P.O.B 9001, Beer-Sheva 8419001, Israel
Department of Electro-Optics engineering and Photonics, School of Electrical and Computer Engineering, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Center for Multidisciplinary Research on Aging, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
Authors to whom correspondence should be addressed.

Received: 01 Feb 2023    Accepted: 03 Mar 2023    Published: 07 Mar 2023   


Currently, low dose radiotherapy (LDRT) is being tested for treating life-threatening pneumonia in COVID-19 patients. Despite the debates over the clinical use of LDRT, some clinical trials have been completed, and most are still ongoing. Ultraviolet C (UVC) irradiation has been proven to be highly efficient in inactivating the coronaviruses, yet is considerably safer than LDRT. This makes UVC an excellent candidate for treating COVID-19 infection, especially in case of severe pneumonia as well as the post COVID-19 pulmonary fibrosis. However, the major challenge in using UVC is its delivery to the lungs, the target organ of COVID-19, due to its low penetrability through biological tissues. We propose to overcome this challenge (i) by using pulsed UVC technologies which dramatically increase the penetrability of UVC through matter, and (ii) by integrating the pulsed UVC technologies into a laser bronchoscope, thus allowing UVC irradiation to reach deeper into the lungs. Although the exact characteristics of such a treatment should yet to be experimentally defined, this approach might be much safer and not less efficient than LDRT.



World Health Organization. Weekly Epidemiological Update on COVID-19—22 January 2023. Available online: (accessed on 3 March 2023).

Su S, Wong G, Shi W, Liu J, Lai ACK, Zhou J, et al. Epidemiology, Genetic Recombination, and Pathogenesis of Coronaviruses. Trends Microbiol. 2016, 24, 490–502. [Google Scholar]
Zu ZY, Jiang MD, Xu PP, Chen W, Ni QQ, Lu GM, et al. Coronavirus Disease 2019 (COVID-19): A Perspective from China. Radiology 2020, 296, E15–E25. [Google Scholar]
Shi H, Han X, Jiang N, Cao Y, Alwalid O, Gu J, et al. Radiological findings from 81 patients with COVID-19 pneumonia in Wuhan, China: A descriptive study. Lancet. Infect. Dis. 2020, 20, 425–434. [Google Scholar]
Dinnon KH 3rd, Leist SR, Okuda K, Dang H, Fritch EJ, Gully KL, et al. SARS-CoV-2 infection produces chronic pulmonary epithelial and immune cell dysfunction with fibrosis in mice. Sci. Transl. Med. 2022, 14, eabo5070. [Google Scholar]
Grillo F, Barisione E, Ball L, Mastracci L, Fiocca R. Lung fibrosis: An undervalued finding in COVID-19 pathological series. Lancet. Infect. Dis. 2021, 21, e72. [Google Scholar]
Tanni SE, Fabro AT, de Albuquerque A, Ferreira EVM, Verrastro CGY, Sawamura MVY, et al. Pulmonary fibrosis secondary to COVID-19: a narrative review. Expert. Rev. Respir Med. 2021, 15, 791–803. [Google Scholar]
Delpino MV, Quarleri J. SARS-CoV-2 Pathogenesis: Imbalance in the Renin-Angiotensin System Favors Lung Fibrosis. Front. Cell Infect. Microbiol. 2020, 10, 340. [Google Scholar]
Bazdyrev E, Rusina P, Panova M, Novikov F, Grishagin I, Nebolsin V. Lung Fibrosis after COVID-19: Treatment Prospects. Pharmaceuticals 2021, 14, 807. [Google Scholar]
Hama Amin BJ, Kakamad FH, Ahmed GS, Ahmed SF, Abdulla BA, Mohammed SH, et al. Post COVID-19 pulmonary fibrosis; a meta-analysis study. Ann. Med. Surg. 2022, 77, 103590. [Google Scholar]
Koosha F, Pourbagheri-Sigaroodi A, Bakhshandeh M, Bashash D. Low-dose radiotherapy (LD-RT) for COVID-19-induced pneumopathy: a worth considering approach. Int. J. Radiat. Biol. 2021, 97, 302–312. [Google Scholar]
Salomaa S, Bouffler SD, Atkinson MJ, Cardis E, Hamada N. Is there any supportive evidence for low dose radiotherapy for COVID-19 pneumonia? Int. J. Radiat. Biol. 2020, 96, 1228–1235. [Google Scholar]
Prasanna PG, Woloschak GE, DiCarlo AL, Buchsbaum JC, Schaue D, Chakravarti A, et al. Low-Dose Radiation Therapy (LDRT) for COVID-19: Benefits or Risks? Radiat. Res. 2020, 194, 452–464. [Google Scholar]
Das IJ, Kalapurakal JA, Mittal BB. Caution warranted for low-dose radiation therapy for Covid-19. Br. J. Radiol. 2021, 94, 20200466. [Google Scholar]
Hanna CR, Robb KA, Blyth KG, Jones RJ, Chalmers AJ. Clinician Attitudes to Using Low-Dose Radiation Therapy to Treat COVID-19 Lung Disease. Int. J. Radiat. Oncol. Biol. Phys. 2021, 109, 886–890. [Google Scholar]
Ghaznavi H. Effectiveness of low-dose radiation therapy to improve mortality of COVID-19. J. Cancer Res. Clin. Oncol. 2021, 147, 2621–2624. [Google Scholar]
The International Commission on Radiological Protection. The 2007 Recommendations of the International Commission on Radiological Protection. Available online: (accessed on 3 March 2023).
Dai T, Vrahas MS, Murray CK, Hamblin MR. Ultraviolet C irradiation: An alternative antimicrobial approach to localized infections? Expert. Rev. Anti. Infect. Ther. 2012, 10, 185–195. [Google Scholar]
Kowalski W. Ultraviolet Germicidal Irradiation Handbook; Springer: Berlin/Heidelberg, Germany; 2009
Buonanno M, Welch D, Shuryak I, Brenner DJ. Far-UVC light (222 nm) efficiently and safely inactivates airborne human coronaviruses. Sci. Rep. 2020, 10, 10285. [Google Scholar]
Kitagawa H, Nomura T, Nazmul T, Omori K, Shigemoto N, Sakaguchi T, et al. Effectiveness of 222-nm ultraviolet light on disinfecting SARS-CoV-2 surface contamination. Am. J. Infect. Control. 2021, 49, 299–301. [Google Scholar]
Ramos CCR, Roque JLA, Sarmiento DB, Suarez LEG, Sunio JTP, Tabungar KIB, et al. Use of ultraviolet-C in environmental sterilization in hospitals: A systematic review on efficacy and safety. Int. J. Health Sci. 2020, 14, 52–65. [Google Scholar]
Storm N, McKay LGA, Downs SN, Johnson RI, Birru D, de Samber M, et al. Rapid and complete inactivation of SARS-CoV-2 by ultraviolet-C irradiation. Sci. Rep. 2020, 10, 22421. [Google Scholar]
Criscuolo E, Diotti RA, Ferrarese R, Alippi C, Viscardi G, Signorelli C, et al. Fast inactivation of SARS-CoV-2 by UV-C and ozone exposure on different materials. Emerg. Microbes Infect. 2021, 10, 206–210. [Google Scholar]
Ash C, Dubec M, Donne K, Bashford T. Effect of wavelength and beam width on penetration in light-tissue interaction using computational methods. Lasers Med. Sci. 2017, 32, 1909–1918. [Google Scholar]
International Commission on Illumination. Technical report—UV-C Photocarcinogenesis Risks from Germicidal Lamps. Vienna. Available online: (accessed on 3 March 2023).
Bialka KL, Demirci A, Walker PN, Puri VM. Pulsed UV-Light Penetration of Characterization and the Inactivation of Escherichia Coli K12 in Solid Model Systems. Trans. ASABE 2008, 51, 195–204. [Google Scholar]
Do-Kyun K, Dong-Hyun K. Elevated Inactivating Efficacy of a Pulsed UV-C Light-Emitting Diode System on Foodborne Pathogens on Selective Media and Food Surfaces. Appl. Environ. Microbiol. 2018, 84, e01340-318. [Google Scholar]
Vachani A, Haas AR, Sterman DH. Bronchoscopy. In Clinical Respiratory Medicine, 4th ed.; Spiro SG, Silvestri GA, Agustí A, Eds.; Elsevier Inc: Philadelphia, PA, USA; 2012, pp. 154–173.
Levitzky MG. Function and Structure of the Respiratory System. In Pulmonary Physiology, 8th ed.; McGraw-Hill: New York, NY, USA, 2013.
Wu G, Yang P, Xie Y, Woodruff HC, Rao X, Guiot J, et al. Development of a clinical decision support system for severity risk prediction and triage of COVID-19 patients at hospital admission: an international multicentre study. Eur. Respir. J. 2020, 56, 2001104. [Google Scholar]
Karthik R, Menaka R, Hariharan M, Won D. CT-based severity assessment for COVID-19 using weakly supervised non-local CNN. Appl. Soft. Comput. 2022, 121, 108765. [Google Scholar]
Gambichler T, Schmitz L. Ultraviolet A1 Phototherapy for Fibrosing Conditions. Front. Med. 2018, 5, 237. [Google Scholar]
Farooqi S, Mumtaz A, Arif A, Butt M, Kanor U, Memoh S, et al. The Clinical Manifestations and Efficacy of Different Treatments Used for Nephrogenic Systemic Fibrosis: A Systematic Review. Int. J. Nephrol. Renovasc. Dis. 2023, 16, 17–30. [Google Scholar]
Tran KT, Prather HB, Cockerell CJ, Jacobe H. UV-A1 therapy for nephrogenic systemic fibrosis. Arch. Dermatol. 2009, 145, 1170–1174. [Google Scholar]
Welch D, Buonanno M, Grilj V, Shuryak I, Crickmore C, Bigelow AW, et al. Far-UV-C light: A new tool to control the spread of airborne-mediated microbial diseases. Sci. Rep. 2018, 8, 2752. [Google Scholar]
Narita K, Asano K, Naito K, Ohashi H, Sasaki M, Morimoto Y, et al. 222-nm UVC inactivates a wide spectrum of microbial pathogens. J. Hosp. Infect. 2020, 105, 459–467. [Google Scholar]
Buonanno M, Ponnaiya B, Welch D, Stanislauskas M, Randers-Pehrson G, Smilenov L, et al. Germicidal Efficacy and Mammalian Skin Safety of 222-nm UV Light. Radiat. Res. 2017, 187, 483–491. [Google Scholar]
Narita K, Asano K, Morimoto Y, Igarashi T, Nakane A. Chronic irradiation with 222-nm UVC light induces neither DNA damage nor epidermal lesions in mouse skin, even at high doses. PLoS ONE 2018, 13, e0201259. [Google Scholar]
Yamano N, Kunisada M, Kaidzu S, Sugihara K, Nishiaki-Sawada A, Ohashi H, et al. Long-term Effects of 222-nm ultraviolet radiation C Sterilizing Lamps on Mice Susceptible to Ultraviolet Radiation. Photochem. Photobiol. 2020, 96, 853–862. [Google Scholar]
Ponnaiya B, Buonanno M, Welch D, Shuryak I, Randers-Pehrson G, Brenner DJ. Far-UVC light prevents MRSA infection of superficial wounds in vivo. PLoS ONE 2018, 13, e0192053. [Google Scholar]
Buonanno M, Randers-Pehrson G, Bigelow AW, Trivedi S, Lowy FD, Spotnitz HM, et al. 207-nm UV light—a promising tool for safe low-cost reduction of surgical site infections. I: in vitro studies. PLoS ONE 2013, 8, e76968. [Google Scholar]
Buonanno M, Stanislauskas M, Ponnaiya B, Bigelow AW, Randers-Pehrson G, Xu Y, et al. 207-nm UV Light-A Promising Tool for Safe Low-Cost Reduction of Surgical Site Infections. II: In-Vivo Safety Studies. PLoS ONE 2016, 11, e0138418. [Google Scholar]
Eadie, E, Barnard IMR, Ibbotson SH, Wood K. Extreme Exposure to Filtered Far-UVC: A Case Study. Photochem. Photobiol. 2021, 97, 527–531. [Google Scholar]
Hickerson RP, Conneely MJ, Tsutsumi SKH, Wood K, Jackson DN, Ibbotson SH, et al. Minimal, superficial DNA damage in human skin from filtered far‐ultraviolet‐C (UV‐C). Br. J. Dermatol. 2021, 184, 1197–1199. [Google Scholar]
Goh JC, Fisher D, Hing ECH, Hanjing L, Lin YY, Lim J, et al. Disinfection capabilities of a 222 nm wavelength ultraviolet lighting device: a pilot study. J. Wound Care. 2021, 30, 96–104. [Google Scholar]
Fukui T, Niikura T, Oda T, Kumabe Y, Ohashi H, Sasaki M, et al. Exploratory clinical trial on the safety and bactericidal effect of 222-nm ultraviolet C irradiation in healthy humans. PLoS ONE 2020, 15, e0235948. [Google Scholar]
International Commission on Non-Ionizing Radiation Protection. Guidelines on limits of exposure to ultraviolet radiation of wavelengths between 180 nm and 400 nm (incoherent optical radiation). Health Phys. 2004, 87, 171–186. [Google Scholar]
Del Bino S, Bernerd F. Variations in skin colour and the biological consequences of ultraviolet radiation exposure. Br. J. Dermatol. 2013, 169, 33–40. [Google Scholar]
Sender R, Bar-On YM, Gleizer S, Bernshtein B, Flamholz A, Phillips R, et al. The total number and mass of SARS-CoV-2 virions. Proc. Natl. Acad. Sci. USA 2021, 118, e2024815118. [Google Scholar]
Cypel M, Feld JJ, Galasso M, Pinto Ribeiro RV, Marks N, Kuczynski M, et al. Prevention of viral transmission during lung transplantation with hepatitis C-viraemic donors: an open-label, single-centre, pilot trial. Lancet Respir. Med. 2020, 8, 192–201. [Google Scholar]
Rezaie A, Melmed GY, Leite G, Mathur R, Takakura W, Pedraza I, et al. Endotracheal Application of Ultraviolet A Light in Critically Ill Patients with Severe Acute Respiratory Syndrome Coronavirus 2: A First-in-Human Study. Adv. Ther. 2021, 38, 4556–4568. [Google Scholar]
Narita K, Asano K, Morimoto Y, Igarashi T, Hamblin MR, Dai T, et al. Disinfection and healing effects of 222-nm UVC light on methicillin-resistant Staphylococcus aureus infection in mouse wounds. J. Photochem. Photobiol. B 2018, 178, 10–18. [Google Scholar]
Hale GM, Querry MR. Optical constants of water in the 200-nm to 200-µm wavelength region. Appl. Opt. 1973, 12, 555–563. [Google Scholar]
Creative Commons

© 2024 by the authors; licensee SCIEPublish, SCISCAN co. Ltd. This article is an open access article distributed under the CC BY license (