A year ago, I wrote an article for The Conversation about a mysterious outbreak of pneumonia in the Chinese city of Wuhan, which was apparently the start of the COVID-19 pandemic.
At the time this article was written, very little was known about the disease and the virus that caused it, but I warned about concerns about emerging coronaviruses, citing SARS, MERS and others as important examples.
Since then – and every day since then – we have continued to learn a lot about SARS-CoV-2 and COVID-19, finding new ways to control the pandemic and undoubtedly keep us safer in the decades to come.
Here’s what we’ve learned since last January and what we still need to learn.
Lessons learned
Initially, the disease we now call COVID-19 was described in terms of lung inflammation, or pneumonia, in the elderly. But now we know that SARS-CoV-2 infection can result in a wide range of symptoms in people of all ages, from none at all to systemic inflammation and death.
And then there are the persistent symptoms that many suffer from – the so-called “long COVID”. We are also beginning to separate the different stages of the disease, the damage caused to organs (such as the heart and brain) and the role of co-infections with bacteria and fungi.
In January 2020, there was limited evidence of human-to-human transmission. If there were, it was thought to be similar to the cousin SARS-CoV-1 virus, which causes SARS, in which the infection spreads relatively late in the disease, when symptoms are at their peak.
However, early studies showed that spread among people was highly efficient for SARS-CoV-2 and that it could happen quickly and before the onset of the worst symptoms. This made control difficult without sensitive and specific tests, using the now famous PCR test.
Social distance, hygiene and masks would help to limit dissemination alongside isolation and quarantine.
In the beginning, there were no treatments or vaccines against COVID-19, in addition to hospital support, such as oxygen supply when the patient had difficulty breathing or antibiotics when he got a secondary bacterial infection.
In the months after January, researchers quickly tested new therapies against COVID-19, identifying dexamethasone, and developed many safe and highly effective vaccines against COVID-19 that are now in use.
Future issues
Although we are learning daily about COVID-19, several important scientific questions remain that will shape the future of SARS-CoV-2 and humanity for decades. The first is how will SARS-CoV-2 evolve, adapt and change in the coming year in the face of natural or acquired immunity through vaccination?
A second, less academic, point would be whether this is important. Our treatments and public health measures will still work, but what about our vaccines?
We continue to track, predict and understand the evolution of SARS-CoV-2 in relation to the ‘escape’ of the vaccine, and all of our available evidence suggests that it is minimal, at best, and that our current vaccine platforms are robust o enough to support any changes, if necessary.
We should also be aware of the chance that SARS-CoV-2 will establish itself in another species, such as mink.
Then there is the question of how SARS-CoV-2 will interact with the other viruses that circulate in humans. The human respiratory tract is home to several viruses that circulate together – usually in a single person.
These viruses promote or prevent infection from other viruses. We now know that, thanks to social detachment, the spread of most of our respiratory viruses, such as influenza and RSV, has been severely restricted.
How will they “react” when mitigation measures, such as social detachment, are over?
Finally, we must identify the origin of SARS-CoV-2 to prevent the continued spillage of SARS-CoV-2-like (or even other pathogenic coronaviruses) in humans.
We know that SARS-CoV-2 probably appeared recently in Southeast Asia and that, ultimately, the virus was on a horseshoe bat. But the biological and ecological steps needed to reach humans remain unclear.
Solving this puzzle will help protect our health for decades to come, just as it did for swine and bird flu infections.
As I said in my article a year ago, these epidemics “are a constant reminder of the need to invest in research on the biology and evolution of emerging viruses and, ultimately, to identify safe and effective drugs to treat – or vaccines to prevent – serious diseases” .
The COVID-19 pandemic has shown that science and scientists can and will deliver results, provided they have adequate financial and social support. How then will we apply the lessons from COVID-19 to other serious problems, such as emerging infections, antimicrobial resistance and climate change?
Connor Bamford, researcher, Virology, Queen’s University Belfast.
This article was republished from The Conversation under a Creative Commons license. Read the original article.