Coronavirus has been with us for a year. Here's what we still don't know

Updated 0056 GMT (0856 HKT) December 29, 2020

(CNN)When China first reported cases of coronavirus to the World Health Organization on December 31, 2019, it was described as a mysterious new strain of pneumonia. It didn't even have a name.

Within two weeks, Chinese scientists had identified the virus' genome sequence, the genetic code that makes up the virus. Within three weeks, the first test kits had been created and then shared by the WHO. And just over 11 months since the virus was reported to the WHO, the first people were vaccinated, making the shots the fastest vaccines ever developed.
The speed at which we've learned about coronavirus is unprecedented and scientists say we already know a remarkable amount.

Covid-19 reported cases and deaths

But one year on, with more than 81 million reported infections and 1.7 million deaths around the world, there's still a lot we don't know about Covid-19.
Those unknowns range from the basics -- such as how the virus started -- to the more complicated questions, including how will this pandemic end?