Here’s the latest on the some of the key questions that researchers are working to answer.
Where did COVID-19 come from?
We know that COVID-19 is caused by a newly discovered type of coronavirus (SARS-CoV2), but we don’t yet know where the virus originated.
We do know that coronaviruses spread among animals and they are zoonotic – meaning sometimes they can pass from animals to people.
Rapid genetic sequencing of the virus has shown that it is very similar to a known bat virus found in China, and to the SARS coronavirus which spread rapidly in 2002. It’s likely that the virus originated in bats, but current theories suggest an intermediate animal passed it on to humans. Studies are underway to help researchers understand which animal transmitted the virus and how, and what is needed to prevent infections from animals in future.
Rumours and misinformation have circulated on its origin, including a theory that the virus was man-made. However, a Wellcome-supported analysis of the virus genome, led by researchers at Scripps Research, has confirmed that the virus was not made in a laboratory or otherwise engineered.
How does the disease spread and how deadly is it?
COVID-19 is a disease that spreads from person to person. When an infected person coughs or exhales, respiratory droplets are dispersed in the air or on surfaces. These droplets can infect other people directly, or infect those who touch a contaminated surface, and then touch their eyes, nose or mouth.
We are less certain on the fatality rate of COVID-19, but experts are working hard to collect data on the case fatality rate, which means the risk that someone who develops the disease will eventually die. Calculations from available data suggest this rate is around 2%, making it more deadly than seasonal flu (~0.1%), but far less deadly than some coronavirus diseases that affect humans, which include SARS (~11%) and MERS (~35%). This number will change over time, as we gain a better understanding of how many people have actually been infected with the virus.
There’s clear evidence that, much like seasonal flu, the risk of death increases depending on an individual’s age and whether they have underlying health conditions. The elderly and immunocompromised are the most vulnerable groups. Adults with underlying heart or respiratory conditions, including smokers and those with diabetes, also have a higher chance of developing fatal complications.
How do you test for COVID-19?
There are two types of test.
1. A test to show if someone currently has the coronavirus
This test indicates whether someone has the coronavirus and therefore their condition needs monitoring. Nose and throat swabs are taken from patients, and the test – called real-time reverse transcriptase PCR – looks for the genetic sequences specific to the virus.
Nearly all of the testing currently happening around the world is done this way. It is highly accurate, but each test has to go to a lab for analysis, so it can be time-consuming and needs specialist training.
Efforts have been made to scale-up the roll-out of these tests around the world. To support the effort in the UK, universities have been donating equipment and volunteering staff to work in dedicated diagnostic facilities. Wellcome has joined the UK government, academic bodies and partners in industry to support the UK’s diagnostic capacity.
A key research priority is to develop a rapid diagnostic test. This would enable faster detection of those infected and remove the need for specialised laboratories.
2. A test for antibodies against the virus, to show if someone has had it in the past
Research is continuing into the development of a test for antibodies against the virus, to indicate if someone has already had it, however mild their symptoms. Also known as serological testing, the aim of this is to determine if people are immune, and how long immunity lasts for.
It’s hoped these tests could be done at home. They could involve a finger prick blood test, giving a result in 15-30 minutes. However, despite a great deal of research currently happening, there is not yet a definitive test which is widely available.
Both tests have a crucial role to play in tackling COVID-19. Together, they provide vital information to help governments decide on implementing and relaxing physical distancing measures, and researchers to develop successful treatments and vaccines.