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Coronavirus and the Sun: a Lesson from the 1918 Influenza Pandemic

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Excerpted from by Richard Hobday

Fresh air, sunlight, and improvised face masks seemed to work a century ago; and they might help us now. When new, virulent diseases emerge, such as SARS and Covid-19, the race begins to find new vaccines and treatments for those affected.


As the current crisis unfolds, governments are enforcing quarantine and isolation, and public gatherings are being discouraged. Health officials took the same approach 100 years ago when influenza was spreading around the world.

The results were mixed. But records from the 1918 pandemic suggest one technique for dealing with influenza — little-known today — was effective. Some hard-won experience from the greatest pandemic in recorded history could help us in the weeks and months ahead.

Put simply, medics found that severely ill flu patients nursed outdoors recovered better than those treated indoors. A combination of fresh air and sunlight seems to have prevented deaths among patients; and infections among medical staff. There is scientific support for this. Research shows that outdoor air is a natural disinfectant. Fresh air can kill the flu virus and other harmful germs. Equally, sunlight is germicidal and there is no evidence it can kill the flu virus.


The open-air treatment of pandemic influenza.

The H1N1 “Spanish flu” outbreak of 1918-1919 was the most devastating pandemic on record, killing between 50 million and 100 million people. Should the next influenza pandemic prove equally virulent, there could be more than 300 million deaths globally. The conventional view is that little could have been done to prevent the H1N1 virus from spreading or to treat those infected; however, there is evidence to the contrary.

Records from an “open-air” hospital in Boston, Massachusetts, suggest that some patients and staff were spared the worst of the outbreak. A combination of fresh air, sunlight, scrupulous standards of hygiene, and reusable face masks appear to have substantially reduced deaths among some patients and infections among medical staff. Equally, other measures adopted during the 1918 pandemic merit more attention than they currently receive.


Sunlight and Influenza Infection

Putting infected patients out in the sun may have helped because it inactivates the influenza virus. It also kills bacteria that cause lung and other infections in hospitals. During the First World War, military surgeons routinely used sunlight to heal infected wounds. They knew it was a disinfectant. What they didn’t know is that one advantage of placing patients outside in the sun is they can synthesize vitamin D in their skin if sunlight is strong enough. This was not discovered until the 1920s. Low vitamin D levels are now linked to respiratory infections and may increase susceptibility to influenza.


Come into a rhythm.

Our body’s biological rhythms appear to influence how we resist infections. New research suggests they can alter our inflammatory response to the flu virus. As with vitamin D, at the time of the 1918 pandemic, the important part played by sunlight in synchronizing these rhythms was not known.

For a lot of people experiencing the stark realities of living during a pandemic and having to stay inside so much is a hard transition. People love going outside and enjoying the elements. Staying inside sheltering at home can be challenging both mentally and physically.

Not going outside and absorbing the sun’s radiant vitality can affect your whole being from energy and sleep to moods and immunity. It can disrupt your sleep cycles, make you irritable, depressed as well as feeling fatigued and that’s because of everyone needs… all those nutrients you get from the sun.