The coronavirus has mutated since the first outbreak began in December. A new Chinese study shows that we are now fighting against two different strings of the virus,
Researchers say it is now two types of the same coronavirus that we fight against - and most infected ones have the most aggressive form.
At least 220,000 people have been infected around the world and almost 8,900 have died from the coronavirus disease, while at least 85,000 have recovered as of 19th of March.
A team of experts from Beijing and Shanghai say that 70% of those infected people have been exposured to the most aggressive form of the virus, but that the disease makes people so ill that patients are quarantined before the disease reaches the point of infection. Therefore, the aggressive form is less contagious. That's what the Daily Mail writes.
We know that viruses can mutate and it can make it more difficult to monitor and treat. It also increases the risk that patients who have ever had COVID-19 may become infected again.
The experts warn that the study is very small and consists of only 103 samples, so more studies are needed. Another researcher adds that it is normal for a virus to change when it passes from animal to human.
The study was made by experts from Peking University in Beijing, Shanghai University and the Chinese Academy of Sciences.
In the study of genes from 103 samples with the specific coronavirus called COVID-19, two different versions of the disease have been found. The researchers called these versions L and S.
The researchers believe that about 70% of all patients have the L version, which is more aggressive and spreads faster than S.
But the L version has become less common during the outbreak because it has had difficulty spreading. The S version, on the other hand, has become more common.
S is less aggressive but is thought to be the first version of the virus that could infect humans and it continues to infect more and more.
This may be because the disease is less severe, so people carry it longer before they end up in the hospital, and therefore there is a greater risk that they can become infected.
In the research article, the researchers led by Professor Jian Lu and Dr. Jie Cui:
"Although the L-type is seen more frequently at the beginning of the outbreak in Wuhan, the number of L-type patients has decreased since the beginning of January."
“Human interference has put pressure on the spread of the more aggressive L-type, which seems to spread faster. On the other hand, the S-type which is older is evolutionarily less aggressive, but is still spreading because people experience symptoms after going on for several days. ”
The researchers' explanation points to the fact that the L-string, which we saw at the beginning of the outbreak, made people so ill that they were quickly isolated, and therefore we were curbed for the spread.
A virus' goal is to make people so sick that they spread it through cough or sneeze, but not sick enough to stay in bed or even die.
If the virus cannot spread to more people it dies and evolution will let another strand become the dominant one.
The S-string is immediately the most dominant now because it causes milder symptoms and it takes longer for people to get sick.
Professor Jian and Dr. Jie adds:
"These conclusions point to an urgent need for more research so that we can combine different data and examine the two strings more closely."
A British researcher who was not part of the study says it is far too early to claim that covid-19 has mutated.
Dr Stephen Griffin from The University of Leeds says:
“Once this type of virus passed on to humans that usually means it is already adapted to us. So they undergo some changes which allow them to adapt and get better at spreading between people. Since this study has not tested the relative "suitability" of these viruses when replicated in human cells or animals, it is not really possible to say whether this is what happened to SARS-CoV2. "
He also points out that the difference between these two types gives no insight into the fatality risks of these coronavirus strings.
The study was published in the scientific journal National Science Review, administered by the Chinese Academy of Sciences.
This post was published on March 19, 2020 7:07 pm