In February, experts thought masks were unsafe. Here's what they've learnt about COVID-19

When COVID-19 emerged, doctors knew almost nothing about how it spread, what it did to people or how to treat it.

source https://www.smh.com.au/national/in-february-experts-thought-masks-were-unsafe-here-s-what-they-ve-learnt-about-covid-19-20201021-p56794.html?ref=rss&utm_medium=rss&utm_source=rss_feed