Of all commonly used indoor materials, naked wood has by far the highest moisture buffering ability, followed by naked plasters (mud or lime). Which is terribly important if we want to keep a room inside the 40-60% ideal hygienic humidity zone. Wood regulates humidity by 65-97%. 
On the other hand, modern materials (coated dry wall, plastic wallpapers, acoustic panels, polyester upholstery, glass, linoleum flooring etc.) has almost no effect on indoor humidity at all which means your room is completely at mercy of the ambient humidity (season, climate).
Why is the moisture level of a room important? Viruses love dry air. This is one major reason influenza spreads in the winter when ambient air humidity drops below 35% for months at a time.
This is big: "A Mayo Clinic study of a preschool where half of the school was given humidifiers in winter and half were not. They specifically tracked flu rates and found that in the humidified half of the school the absenteeism rate dropped by about 66%." boston25news.com/news/is-humidi…
In conclusion: a room with more wood (naked is better) naturally regulates the indoor humidity to neutralize viruses, such as influenza. Modern materials offer no help at all, that is why people have to spend lots of money, electricity, and floor space, on air humidifiers.
Related: Swedes know ALL about indoor humidity and air quality. Look at this room: solid log walls coated with clay and finished with paper: it is like a humidity buffering professional's wet dream!
Source for humidity buffering room lining studies on different materials (a big pdf from Frauhofer Institut Bauphysik, commissioned by German Federal Ministry of Economics and Labour): wufi.de/literatur/K%C3…
“When we dry the air out droplets & skin flakes carrying viruses and bacteria are launched into the air, traveling far and over long periods of time. The microbes that survive this launching tend to be the ones that cause healthcare-associated infections.” forbes.com/sites/leahbind…
If you have kids in school or relatives in hospital, put one of these in their rooms, it is about $10. Tell them to tell you if it ever drops under the 40-60% safe zone, and if it does you know you need a long chat with the principal.
