What are masks for?
Face masks are to protect other people. There is now sufficient scientific evidence that coronavirus is transmitted via close contact and droplets. Face masks offer sufficient protection against droplet transmission. An infected individual can unknowingly be infectious two days before symptoms appear. So if everybody wears a mask in enclosed spaces, every individual is protected against everybody else. Wearing a mask does not guarantee one hundred percent protection, but it does slow the spread of coronavirus.
Because many people do not show symptoms but could still be infected, masks should also be worn in solidarity with at-risk groups. Individuals who are particularly at-risk have an increased chance of becoming seriously ill. This includes, in particular, older people, pregnant women and people with pre-existing conditions. These groups of individuals require particular protection.
The effectiveness of face masks has now been proven in studies. In particular, we are drawing upon the following two policy briefs of the Swiss National COVID-19 Science Task Force (https://ncs-tf.ch/de/):
How do I wear a face mask or cloth face covering correctly?
How do I use a face mask correctly?