Thomas Boswell
Just a few months ago we didn’t even know coronavirus existed, but thanks to some quick-thinking studies and data collected from millions of sufferers, scientists have been able to work out a lot about how the disease works and how it spreads through a population.
But it’s still very early days. Many big questions about coronavirus remain unanswered. To really win the fight against coronavirus, scientists will need to answer these – and many more. Only then can we return to normality, or at the very least a new kind of normal.
1. How many people have already been infected with Covid-19?
For some people, catching coronavirus will feel a bit like getting a mild cold. For others, they may not notice they’ve been infected at all. For others, it’s a death sentence. At best, official figures around the world count hospital admissions and deaths as well as deaths in care homes and cases in the community that have been tested. But that leaves a lot of coronavirus cases going undetected.
As the World Health Organization has advised: test, test, test. In the UK, testing is being ramped up to include care homes, essential workers and their families, and people over the age of 65 and their households – if someone has symptoms. But even this won’t cover everyone. In fact, even if the UK meets its target of testing 100,000 people a day, it still won’t give us a completely accurate picture of how far the virus has spread.
The only way we will know is through antibody testing, a method which checks your blood to see if your body has produced coronavirus-fighting antibodies. This proves that you’ve had the disease. This way everyone – even those who had the disease with no symptoms, can be counted. As of yet, it’s unclear how reliable these tests will be, and so officials are unwilling to roll them out.
2. Does infection give you lasting immunity?
When a virus first enters the body, it produces an immune response. Your body produces antibodies that will fend off the virus so that you recover and, in some instances, maintain an immunity. But the body remembers how to fight some viruses better than others – that’s why you’re unlikely to get chickenpox twice in your life, but you could get the common cold twice in a year.
Covid-19 hasn’t been around long enough for scientists to understand how long the body’s immune system can remember it for. No studies have been able to tell whether antibodies mean that you’re immune, and some reports have even claimed that some patients have tested positive for the virus for a second time. It will take time – and multiple studies – to truly understand whether patients are immune after recovering from the virus, and for how long.
3. How much transmission is asymptomatic?
While some people experience symptoms so severe they struggle to breathe, others experience no noticeable symptoms whatsoever. But what proportion of people this amounts to remains unclear.
One study published in the journal Eurosurveillance estimated that the proportion of asymptomatic cases was 17.9 per cent, after looking at passengers quarantined on the Diamond Princess cruise ship in February. But another study published in the journal Science estimated that as many as 86 per cent of cases could go undocumented as they have little or no symptoms. The only way to tell is through widespread antibody testing, which remains some way off.
4. Why do some people get much more ill with Covid-19?
Studies have tried to determine the risk factors of Covid-19. One study of 201 patients, published in the journal JAMA Internal Medicine, found that older age was one of the leading factors of acute respiratory distress and death in coronavirus patients. However there have been many young people who have been sent to hospital with severe symptoms, even though they appear not to have any underlying health conditions.
A study published in The Lancet, estimated that the fatality rate of coronavirus was 1.4 per cent in those younger than 60 and 4.5 per cent in those over 60. Though older people are more likely to die with the disease, it doesn’t mean that younger people won’t. Even within age groups, there is a big variation in the severity of symptoms, with some being asymptomatic and some on the brink of death. It’s thought that specific genetic variations could increase the severity of coronavirus in some patients, while smokers may even be less likely to contract coronavirus.
5. What long term effects does Covid-19 cause?
The virus attacks the brain, heart and intestines, as well as the lungs. In 70 patients who had survived Covid-19, 66 had lung damage visible in CT scans, according to a report published in the journal Radiology. A study of 214 patients in Wuhan found that 36.4 per cent had neurological symptoms such as headaches, dizziness and hallucinations. But it is unclear what lasting effects these symptoms may have.
There are also reports of young and middle-aged people suffering strokes. In China, researchers examined the blood of Covid-19 survivors and found that it may have an impact on the heart and liver functions of some patients. While these findings are concerning, much larger groups will need to be studied in order to come to any conclusions.
6. Will there be a second wave?
One of the five tests the UK will have to pass before the current lockdown is the country’s ability to handle a second wave. But some say a second wave is inevitable, including Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases and a key member of the White House’s coronavirus task force.
The Institute of Economic Affairs, a think tank, predicts that the coronavirus will last for up to two years and will come in a series of waves. It bases this prediction on historical cases, such as the Spanish influenza pandemic of 1918 which came in three waves with the second being the most deadly.
But, as with all the predictions, modelling and speculation, it’s impossible to know for sure whether there will be a second wave, how significant it will be and the impact it will have.
7. How much do children spread the disease?
Although Ofstead has said that reopening schools would be in the children’s best interests, it remains unclear what role children attending school play in spreading coronavirus. The perceived risk is obvious enough: millions of children go to school, gather in large groups and take the virus home. But it isn’t that simple.
Children are known to be superspreaders of other viruses, such as the common cold and flu. But the vast majority of coronavirus cases in hospitals are adults. A study from China showed that children are rarely diagnosed with the virus, meaning that they may have little part in the spread of the disease. But, once again, there haven’t been enough studies, nor do we have enough data on whether children returning to school significantly accelerates the spread of coronavirus.
Maria Mellor is a writer for WIRED. She tweets from @Maria_mellor
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