The Seqcovid consortium has already processed more than 4,000 coronavirus genome sequences from 20,000 patients. What findings have been the most relevant so far?
We have observed that in the first and in the second hello different genetic variants of the virus has spread rapidly. We saw how in February there were already hundreds of introductions of the virus with different genetic variants. Many of them were unsuccessful. A few did have it and increased its frequency in a short time. One of them was responsible for 60% of the cases in the first wave. This variant entered through Valencia and Madrid and was quickly expanded by a large outbreak that occurred at a funeral.
“SARS-CoV-2 is a very homogeneous virus, the flu virus suffers more mutations”
What happened to the virus during confinement?
With the quarantine almost all variants of the coronavirus disappeared, so this measure was found to be effective.
But with the end of the summer came the second wave.
Yes, then a variant emerged in Spain, which is the one that has colonized a good part of Europe in this second wave. We do not know its exact origin, but the first cases occurred in Aragon. It expanded very quickly from the end of June until it was the dominant variant already in August. With the opening of borders we begin to see more and more cases of this variant distributed throughout Europe.
Have many coronavirus mutations been detected?
Different studies have determined that this virus suffers an average of two mutations every month. The vast majority of these mutations do nothing and occur every time the virus replicates, which is normal.
“The quarantine in Spain was effective, because almost all the variants of the virus disappeared”
When should these mutations concern us?
They would be important if they affected the biology of the virus, for example the way it enters the human cell.
Could they affect the development of some of the vaccines?
Not for the moment. Furthermore, this virus is very homogeneous and we already know how to deal with this diversity thanks to the flu. This virus undergoes four mutations per month, more than SARS-CoV-2 and HIV even more. However, within the consortium we have made a working group to monitor these mutations and see if they have an impact on the vaccines that are being developed.
What makes one coronavirus mutation successful and predominate over the others?
We do not yet know if some of the mutations carried by this dominant variant in the second wave have given it an advantage over the others.
“The complicated thing compared to other coronaviruses is that it is spread before symptoms appear”
A few weeks ago, thousands of minks were euthanized in Denmark after a coronavirus mutation was found that could affect humans. What is known about the transmission of the virus between animals and humans?
We have seen large outbreaks on farms, but we still have a lot to know. It is like a black hole in coronavirus zoonoses and it is something that we must gradually integrate. There are people who are doing interesting things, but there is no global vision.
Why is SARS-CoV-2 different from other coronaviruses?
If you compare it with SARS or MERS, what makes it more difficult to control it is that it is transmitted before the symptoms appear or when they are beginning. This means that when the person is diagnosed with the disease, they have already transmitted it, which makes it more difficult to control it. With the other coronaviruses this did not happen, you were contagious after the first symptoms appeared. Another problem is that between 20 and 40% of coronavirus patients are asymptomatic, which means that surveillance systems have had to adapt to the transmission pattern. This is why it has been so much debated whether symptom-based controls work well with this coronavirus and that is why it is essential to isolate contacts from positive cases as soon as possible. The epidemiological window of this virus is very small and everything has to be very well controlled.
Digsmak is a news publisher with over 12 years of reporting experiance; and have published in many industry leading publications and news sites.