Journal of Photochemistry & Photobiology, B: Biology

2020 [epub pre-publication]

Chukuka Samuel Enwemeka, Violet Vakunseh Bumah, Daniela Santos Masson- Meyers: From San Diego State University, and Marquette University School of Dentistry. This study cites 99 references.


The ongoing battle against the COVID-19 pandemic has prompted a reevaluation of potential clinical tools to mitigate its impact. Amidst this pursuit, a groundbreaking paper highlights the immense potential of phototherapy in reducing the severity of coronavirus diseases. Drawing from historical success during the 1918 influenza pandemic and recent scientific evidence, this article explores the key points presented in the research, shedding light on the promising role of light in combating COVID-19.

Key Findings:

  • Historical Success of Phototherapy:
  • Phototherapy, long regarded as one of the most effective treatments during the 1918 Spanish influenza pandemic, has been historically overlooked. The paper underscores the urgency of revisiting this seemingly forgotten treatment, given the pressing need to address the severe consequences of the current pandemic.
  • Antimicrobial Properties of Light:
  • Violet/blue light in the range of 400–470 nm has proven antimicrobial against various bacteria, and its efficacy has historical roots in Niels Ryberg Finsen’s Nobel-winning treatment of tuberculosis. Recent evidence suggests that blue light can inactivate viruses, including the common flu coronavirus, while red and near-infrared light demonstrate therapeutic benefits for respiratory disorders.
  • Potential for Environmental Sanitization:
  • Violet/blue light has the potential to reduce infections and sanitize environments, including hospital facilities, emergency care vehicles, and homes. Pilot studies have shown promise, indicating the need for further exploration of the clinical value of light in the context of infectious diseases.
  • Overlooked Role in the 1918 Pandemic:
  • Records indicate that phototherapy was one of the most effective tools used to minimize the impact of the 1918 Spanish influenza pandemic. The paper emphasizes that the historical success of phototherapy against bacterial and viral infections has been unjustly overlooked and highlights its potential in the current COVID-19 pandemic.
  • Understanding the Mechanisms:
  • Looking into the mechanisms underlying the antimicrobial effect of blue light, it triggers bacterial chromophores to produce reactive oxygen species, leading to bacterial cell death. Pulsed blue light has shown promise in disrupting the structural architecture of bacterial cell membranes.
  • Therapeutic Value of Red and Near-Infrared Light:
  • Red and near-infrared light have therapeutic value, potentially reducing lung inflammation, fibrosis, and complications associated with coronavirus infections. Clinical results indicate significant improvement in patients with chronic obstructive lung disease, bronchial asthma, and allergies following light therapy.
  • Antiviral Potential of Blue Light:
  • Recent developments suggest that blue light, particularly pulsed blue light, has the potential to inactivate coronaviruses, including COVID-19. Clinical urgency is emphasized to explore these initial results and harness the potential of light as a therapeutic tool.


The exploration of phototherapy as a potential treatment for COVID-19 opens new avenues for research and clinical application. As we navigate the complexities of the ongoing pandemic, the historical success of phototherapy and recent scientific advancements beckon for comprehensive investigations. The urgent call to delve into the therapeutic potential of light resonates as a proactive approach to combating not only COVID-19 but future viral challenges.