Coronavirus: what has changed about what we know? –video explainer
by Sarah Boseley, Alex Healey and Nikhita Chulani from on (#595P1)
Covid-19 has spread around the world, sending millions of people into lockdown as health services struggle to cope. From symptoms and long Covid to vaccines and treatments, the Guardian's health editor, Sarah Boseley, explains what we now know about the virus that we did not at the beginning of the crisis