When China first reported cases of coronavirus to the World Health Organisation 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 eleven 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.
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?
“We have learned a tremendous amount, but in terms of understanding anything in any real detail, we’ve got miles and miles to go,” said Maureen Ferran, an associate professor of biology at Rochester Institute of Technology. “This is going to keep virologists and public health officials busy for decades.”
Where coronavirus originated from
As governments raced to find a vaccine for the virus, one of the most basic questions fell off the public’s radar: what is the origin of the virus?
The virus’ origin has been dogged by confusion and conspiracy theories. Initially, the virus looked like it was connected to a Wuhan market that sold live animals, but a Lancet study published in January found that one-third of the initial patients had no direct connection to that market.
Some, including US President Donald Trump, questioned whether the virus had been released after being studied or created in a Wuhan lab. Scientists say there is overwhelming evidence that the virus originated in the wild and say the closest known relatives to coronavirus are too genetically different from COVID-19 for it to have been leaked and subsequently caused the outbreak.
Studies have found evidence that the virus may have been circulating in the US and Europe in December 2019, months earlier than first thought. Chinese state media has pushed the narrative that the virus may have originated outside of China.
But while Peter Collignon, a professor of microbiology at the Australian National University, says it’s quite likely that the virus was circulating in the US and parts of Europe before the first cases in those countries were diagnosed, there’s nothing conclusive to show that the virus originated outside of China. The World Health Organisation, which is investigating the origin of the virus, will look into whether COVID-19 could have been circulating in China before the first cases were identified in December.
Despite the plethora of conspiracy theories, there are a few things that most scientists agree on. COVID-19 is a coronavirus, a type of virus that is responsible for everything from the common cold to SARS. It’s zoonotic, meaning it originally came from an animal. Some studies point to bats as the likely vectors, which are known to carry coronaviruses. And most scientists still think the virus transferred to humans in China, as that is where the first cases were identified.
But we still don’t know where the virus first passed to humans, and if it transferred through another animal intermediary, such as a pangolin or a civet cat, before infecting humans. Those are questions we may never answer, says Ferran — after all, in the more than 40 years since Ebola was discovered, scientists have not been able to definitively say which animal it came from.
Why it affects some people more than others
When COVID-19 was first identified, it was seen as a respiratory illness. But as the months have gone on, a range of symptoms and complications of the disease have
Many people lose their sense of smell. Some people vomit or have diarrhea or get discoloration on their fingers or toes. Some even have impaired cognition or brain damage.
We now know that even those who recover from COVID-19 can experience long-lasting effects, including anxiety, brain damage and chronic fatigue. A study published in the British Medical Journal in August found that around ten per cent of patients had a prolonged illness from COVID-19 lasting more than 12 weeks.
But scientists don’t know how long these effects from COVID-19 last — and they can’t really explain why it is that some people suffer more than others.