Covid-19 is a pandemic virus that emerged in China (possibly due to a lab leak) and has killed over 4M people worldwide.
It is fatal in around 2% of cases[1] and causes long lasting problems for around 10% of people[2]. Young people are largely unaffected, but do transmit the virus.
Transmission is primarily airborne[3]. The best defenses are vaccines, staying outdoors, ventilation, masks, and rapid-testing.
Deaths have declined in most developed countries due to vaccination. However cases are high worldwide due to to the Delta variant.
