To answer Joe le Taxi I posted a reference last week on the jet blast virus thread about evidence of worrying damage to the lungs amongst a cohort with relatively mild illness (not requiring ICU treatment as reported by doctors at the main hospital in Innsbruck) and there has subsequently been more of the same from other sources. Another issue appears to be that the virus can cause inflammation leading to damage in other organs as well. It is too early to tell how big an issue this is. I am not aware of anyone with these types of injury being reinfected and let's hope that cannot happen. But equally there is no proof to the contrary. There are diseases where previous infection reduces subsequent severity. But there are also examples (like Dengue) which get worse.