Two months ago, in Muy Interesante we wanted to talk with experts from different disciplines to find out what science will bring us in the 2020s. One of the interviewees was Raúl Rivas, professor and researcher in the Microbial Interactions Group of the Department of Microbiology and Genetics from the University of Salamanca , which at that time told us the following: “it is possible that a new epidemic appears, mainly of viral origin, this is something that has a cyclical nature and has not happened for a long time, but it will happen: viruses they recombine, new strains appear and therefore new diseases ”.
The year has barely begun, and that new strain of virus, in this case a coronavirus that causes the Codvid-19 disease, is already with us. We wanted to talk to this researcher again to find out a little more about it.
Your prediction about the emergence of a new viral epidemic has come true almost as soon as it was announced …
Yes, it turns out that every ten years, approximately, we have a new epidemic of some respiratory virus, which is the one that generates more social alarm and has the capacity to spread faster. In 2003 it was SARS, then came MERS in 2012 and now this coronavirus in 2020.
I would also like to emphasize that this has been the first epidemic broadcast in real time, we are informed up to the minute of everything there is , and this has also generated greater alarm, which from my point of view has been excessive. We are talking about a very contagious virus, yes, but the mortality rates are relatively low.
How does a new strain of virus emerge?
Viruses need us, since they cannot reproduce by themselves, and they use our cellular machinery to do so. There are viruses, such as those of hepatitis, that have the key to enter liver cells, and other viruses such as the flu use lung cells. Cell damage occurs there, which triggers a cascade of cytokines in response to the body and generates symptoms such as fever.
Although there may be genetic recombinations between different viruses, it is normal for point mutations to occur, because viruses have fewer mechanisms to combat them. These mutations, sometimes, allow them to have different keys and open new cells that can even be from animal species that they had not infected until that moment.
This has been going on forever. The same thing happened with smallpox, this disease was not with us since we emerged as a species but appeared at a certain time, which is estimated a few thousand years ago. Now we have managed to eradicate it, and with many other viruses the same will happen.
Many of the viruses are in wild animal species with which we are in constant contact. It may happen that some of these viruses, which are continuously mutating, find these new doors of entry. It is not that they adapt immediately to the human being, they usually use intermediate steps that are usually other mammals related to us.
This is the case of these new coronaviruses: in the majority the main reservoir is bats. And is that bats are reservoirs of a multitude of viruses, such as Ebola. Ebola is rarely talked about, but in reality the problem that exists in Africa with this disease should concern us much more.
Under what conditions is this leap from disease to man favored?
China meets the ideal conditions for this: we are talking about a high population density that is in continuous contact with wild animals, because they have live animal markets. These markets, in turn, are also overcrowded, including travelers who are going to visit these tourist attractions.
Those live animals are the ones that ultimately transmit the disease, in the case of SARS it was civets, in the case of MERS it was in the Middle East with dromedaries and now in the case of the coronavirus everything seems to indicate that it is the pangolin, which is It is consumed in some parts of China and its scales are used medicinally in others. Although its trade has been strictly prohibited, there is still a black market, with which the transmission can continue: because we are talking about huge cities of twenty or forty million inhabitants.
It must also be taken into account that the sanitary and hygienic conditions of these markets are not those of the European markets and the controls are not the same. There are many conspiracy theories that say that the coronavirus would be something that they are manipulating, a biological weapon that has escaped … well, it could be, but it is very twisted. And you have to be very clumsy for such a virus to escape you. We are talking about a natural process that has occurred and will always occur.
So we know that new viruses are going to keep emerging, but is there a way to prevent new outbreaks or get ahead of them?
To begin with, the trade and consumption of wild animals must be better controlled. On the other hand, there has been a first attempt to anticipate the outbreak from the hand of artificial intelligence. A company developed a program that, by detecting news that arose from unknown diseases and using other data such as symptoms, predicted what was happening and how it was going to spread.
The program said that it could be a new respiratory disease and that it could be a virus, it located all the flights that could leave the city based on the tourists and it found in which countries the disease would appear outside of China.
Artificial intelligence can help us to know where a focus may appear and how it is going to spread. But eliminating these viruses, or making none appear again, I would say that today is impossible. Viruses are very varied, they will continue to mutate, many of them are in wild animals that are uncontrollable … it is complicated. How do you prevent someone from hunting an animal and putting it up for sale in a crowded country like China or India?
Maybe that’s important to highlight, right? It’s scary that this will suddenly turn into a crusade against wild animals …
Yes, there are very extreme people who may think that the solution is to eradicate bats, for example. Bats are a crucial link in ecosystems, they are also great consumers of insects that, in turn, are vectors of many diseases that affect us. So let’s leave the bats alone.
Now, what you have to be careful is when handling wild animals. If we find dead wild animals, for example, it is best to notify the competent authorities. We must be cautious, also when we travel to countries where we know that the hygienic conditions in the markets are not so controlled, we must be careful with what we eat.
There are other prevention measures that can be taken on an individual level, and they are the same that we take to protect ourselves from the spread of other diseases such as the flu, for example washing our hands well and relatively frequently. Or cover our mouth with the inside of the elbow when coughing, because this way we avoid having the virus on our hands and transmitting them more easily to other people.
How complex is it to find a vaccine for the coronavirus and how much can trials be accelerated?
The World Health Organization in these cases tries to speed up the process and has already indicated that there may be an initial vaccine in a period of six or seven months, but the problem is that this vaccine will protect against this type of virus, not against to others.
This is what happens with the flu, which mutates very easily and when we inoculate ourselves with the vaccine, it immunizes us against the viruses that caused it last year. If the virus has mutated a lot, the vaccine protects us less.
We must also bear in mind that coronaviruses are much more frequent than we might think, in fact the main culprits for the common cold are coronaviruses and rhinoviruses. They have a lot of genetic plasticity, thanks to it sometimes they turn into more aggressive forms and in others of these forms we do not even know. Many affect only population groups at risk, due to being elderly or suffering from other diseases. In healthy people, many of these viruses go unnoticed because they generate milder symptoms.
