From left to right, the participants in the debate on the coronavirus organized in the Science Park of the University of Valencia: Ron Geller, Mireia Coscollá, Santiago F. Elena and Fernando González-Candelas. / Photo: Diana Moret i Soler

Mireia Coscollá, Santiago F. Elena, Ron Geller and Fernando González-Candelas dismantle the myths about the epidemic.

For several weeks, SARS-CoV-2 has been presented to the world's population as if it were a movie villain. Along with its expansion, the alarm bells have flooded the media and social networks to the point of generating a collective state of nerves resulting from ignorance. Faced with this situation, the University of Valencia brought together a committee of experts this Monday to provide scientific data and resolve doubts in a public debate on the new COVID-19 pneumonia epidemic. 

Mireia Coscollá, Santiago F. Elena, Ron Geller and Fernando González-Candelas, members of the Pathogenic Systems Biology Research Program of the Institute of Integrative Systems Biology (Universitat de València-CSIC), were in charge of explaining how the coronavirus affects Spain and resolving the doubts raised during the debate. 

SARS-CoV-2 belongs to an extensive family of viruses that cause human diseases. One of its peculiarities is that it has a very low mutation rate due to its length: between 26 and 32 kilobases compared to the usual 10 kilobases of RNA (ribonucleic acid) viruses. According to the experts, this is relevant because it produces fewer changes in its genome throughout the epidemic process than other viruses that have a higher mutation rate, so we have to develop more immune responses, as in the case of the flu. The SARS-CoV-2 virus is what can cause the disease, called COVID-19.

Bat zoonoses?

The experts explained that any of the emerging coronaviruses have an animal reservoir: rodents, primates, birds, horses... At a given moment, the virus present in the animal jumps to humans and replicates in them. This process is called zoonosis, an animal disease that is transmitted to humans. In the case of the coronavirus, although everything indicates that it is due to a bat zoonosis, a sufficiently similar virus has not yet been found, but the probabilities that it comes from this species are high. What has not yet been discovered is the intermediate host, because the possibilities considered have been highlighted, such as the snake or the pangolin, as explained by Santiago F. Elena, research professor at the CSIC.

Does it affect everyone equally?

We know that SARS-CoV-2 is transmitted through saliva droplets when speaking or sneezing or through contaminated surfaces, where the virus is deposited and remains active for a few hours until it degrades completely. According to Fernando González-Candelas, professor of Genetics at the University of Valencia, differences have been found between those infected. "Within COVID-19 cases, there is a mortality bias between men and women, and young and old," he stated. The sex distinction is due to the fact that men express more the receptor—ACE2—, the cell membrane protein that the virus uses to enter our body. Thus, elderly men are one of the groups with the highest risk of mortality from the coronavirus, especially when it is associated with respiratory diseases, heart disease or diabetes. And if one of the most sensitive groups are older people, why are there young health personnel who have died from the virus? According to González-Candelas, when a young person becomes infected and develops a pathology that can lead to death, the body's reaction mechanism is very different from what happens with elderly and immunocompromised people: "Young people have an immune system so well prepared for an infection that a "cytokine storm" develops that ends up collapsing their lungs due to the excess response to a novel infection, as occurs in some cases of flu," the researcher explained. 

Is reinfection possible?

Ron Geller, researcher at the Viral Biology Group at the University of Valencia, pointed out that, in principle, there is little chance of reinfection by SARS-CoV-2 but in that case, the body will respond with greater immunity than in previous times, generating a lower mortality. According to González-Candelas, there are articles that talk about the possibility of reinfection of the virus, that is, patients who have been discharged and who over time test positive again for the diagnostic test for the virus - PCR positive - but it is still not known if this corresponds to a reinfection or to the possibility that there is some type of undiscovered reservoir that produces small amounts of virus without clinical repercussions. 

Have there been undetected cases of COVID-19 during the winter?

According to Mireia Coscollá, researcher at the Bacterial Pathogenomics Group at the University of Valencia, it is very difficult for Spain to have had cases of infection during the last months of 2019, because all dating estimates for the origin of the virus are located in China as of December. In addition, he explained that it is also difficult to confuse COVID-19 with another infection such as the flu, since the only thing they have in common is a high fever, but while one produces mucus and high muscle pain, the new infection causes a feeling of suffocation. "With COVID-19, apparently there is no generalized muscle pain, therefore symptomatologically they are not easy to confuse," he commented.    

Will there be infection in summer?

Temperature is not a guarantee of a decrease in infection. González-Candelas explained that there are seasonal coronaviruses but we do not know if SARS-CoV-2 is one of them. It is possible that the widespread community disappearance of a virus occurs during the summer, but this does not mean that it is a consequence of this time of year, because there have also been cases of flu during the months of July and August, such as the 2009 flu epidemic. In any case, there is still not enough data to verify whether the new virus will become extinct with the rise in temperatures.

What is Spain's preparation?

At this stage of the epidemic, preparation consists in being clear about where the infection can come from, what the cases are and how they can be diagnosed reliably, and having the health system prepared to accommodate those patients who need it. As an informative measure, the Ministry of Health has published various documents intended to provide updated information on the situation and to set guidelines to follow in the face of the epidemic, intended for both professionals and citizens. One of the current objectives is to avoid community circulation of the virus, as is happening in other parts of the world such as the United States.

At this time, the epidemiological situation in Spain is under control, the experts said, adding that measures such as the cancellation of large events have been considered inconvenient for the moment. Although the committee of researchers hopes that a treatment will be developed that can generate an immune response to SARS-CoV-2, González-Candelas recalled that in the late 1960s it was thought that infections had been put to an end. "Since then we have had new pathogens unknown until now, which will not be the last," explained the professor of Genetics, who added that today's society does not live "in an isolated box" and that "globalization works in every sense."  

«The best antiviral measure would be to close Twitter»

Santiago F. Elena used this phrase to denounce the number of hoaxes that have arisen as a result of the expansion of SARS-CoV-2. In times of social alarm, social networks and the media can contribute to widespread misinformation and this hinders scientific communication and the possibility of taking collective actions to confront the epidemic. The experts concluded the debate by appealing to the common sense of citizens to promote the use of reliable sources and prevent pharmacies' stocks of masks from running out, which, on the other hand, do not protect against the virus. But in case there are still doubts about the pseudo information circulating on the internet, the WHO has published a document where it denies the most bizarre rumors about SARS-CoV-2 that have been discussed so far.

Source: Mètode