New Coronavirus: Scientific Advances And An Unavoidable Challenge
Top 5 Mistakes On New Coronavirus The race to contain the spread of the new coronavirus, SARS-CoV-2, has been fraught with uncertainties. There are still many aspects of this virus that are unknown and, unfortunately, when they are discovered it will be too late for the tens of thousands of people who have died – for now – in the Covid-19 epidemic.
Among the most notable unknowns is, for example, how the virus is transmitted. Surely, the spread is mainly produced by the saliva droplets expelled by infected individuals when they cough or sneeze near other people, but in some scientific forums there is still debate about whether the pathogen can travel longer distances in the form of an aerosol, that is, into even smaller droplets that travel through the air.
However, while it may sometimes seem like sticks are being blind, the research is moving forward and the lessons that are being learned will serve for future waves of this or other viruses. “It is the first time that we know so much about a virus that was discovered just three months ago,” says Ignacio López-Goñi, professor of Microbiology at the University of Navarra. In fact, there are already “over 1,400 scientific articles published on SARS-CoV-2 and the disease it causes.”
These are the most important milestones (and the odd uncertainty) in the investigation of the new coronavirus:
1- What is the virus like and why has it caused so many deaths “It is not that it is a terribly aggressive virus; what sets it apart from others is that it is highly contagious ”, explains Salvador Macip, professor of Health Sciences Studies at the Open University of Catalonia (UOC). Those who study this pathogen have found two main reasons for this enormous transmission capacity:
After infection, there is a phase when the infected person has no symptoms, but already transmits the virus. During this time, the infected person expels viruses without knowing it and without taking precautions.
Those who are sick have a very high viral load. This implies that, for example, in a saliva sample there may be much more of this coronavirus than of its ‘first cousin’ causing the disease known as acute and severe respiratory syndrome (SARS, also known as SARS and SARS), than caused a more contained epidemic in 2002-2003.
The great transmitting power is only part of the explanation for the devastating consequences of Covid-19. The other is the ability of the virus to cause serious problems in a variable proportion of those infected. In this sense, López-Goñi points out that the new coronavirus combines the characteristics of viruses that affect the upper respiratory tract (nostrils and throat) and those that lodge in the innermost areas of the respiratory system, such as the bronchi, lungs or alveoli. “It probably colonizes the two routes and that makes it, on the one hand, being on the upper routes, very transmittable, as a cold could be; but, at the same time, when reaching the inferior routes, it can produce pneumonia ”, he summarizes.
On the other hand, proteins on the surface of the virus have been discovered that have a high affinity for receptors in human cells. Specifically, the coronavirus S protein binds with a high affinity to the ACE2 receptor of cells, which helps explain why it infects our species so successfully and, at the same time, it can be a therapeutic target in the development of vaccines. or therapies.
What You Don’t Know About New Coronavirus: Scientific Advances And An Unavoidable Challenge Could Be Costing To More Than You Think
Another characteristic that explains the lethality of the virus in the most vulnerable groups – older people with previous pathologies – is that it can produce what is known as a cytokine storm, which are small proteins that cells produce when they become infected. “They are like messengers that send signals to our entire immune system,” says López-Goñi. Under normal conditions there is a balance between “the cytokines that produce inflammation and those that remove it.” But in some people with this virus there is an excess production of cytokines that produce inflammation, which leads to the imbalance of the immune system in such a way that, instead of protecting from the virus, it does more damage.
The microbiologist points out that cytokine storms are not unique to this pathogen: “They occurred with other pandemic viruses, such as the 1918 influenza virus.” These serious effects have also been seen in young people and without previous pathologies -although in a much lower percentage-, since apart from age and diseases, factors such as the genetics of each individual and their immunology (that is, their defenses) can influence ).
One of the big questions still unanswered is whether the new coronavirus will disappear when the pandemic ends or stay with us, even if it is no longer with the same intensity. Iván Sanz, head of science and Virological Surveillance at the National Flu Center of Valladolid and microbiologist at the Clinical Hospital of Valladolid, indicates that two possible scenarios are currently being considered: “That the virus become extinct, something that seems very difficult to me because it “It has adapted very well to the human species, or that it becomes seasonal like another virus and in some people causes the symptoms of a cold and in others pneumonia.”
Efforts in the scientific community are focused on the second possibility, with the aim of minimizing the devastating effects of the current Covid-19 epidemic as much as possible. “A pandemic has had to come for us to realize that we have to be prepared,” says Sanz.
3- New uses for old drugs Some of the therapeutic strategies being investigated will give results in the medium or long term. This is the case of vaccines. However, some drugs are already being tested against the new coronavirus that could be saving the lives of many people, although it is still early to assess it. In the words of López-Goñi, “there is no specific medicine for this virus; what is being done is experimentally testing other drugs that we know work on similar viruses. ” Here are some of them:
Chloroquine is an antimalarial that was being discontinued for its side effects and because the malaria parasite was becoming resistant to it. But years ago it was seen that it is a powerful antiviral because it blocks the entry of viruses into the cell. In fact, it has been tested on other viruses. “Now what is being done is using hydroxychloroquine, which is slightly less toxic than chloroquine,” says the microbiologist at the University of Navarra.
Hydroxychloroquine is sometimes combined with antibiotics, but not because the antibiotic does anything against the virus, but because the virus can promote secondary bacterial infections that can be fatal.
Remdesivir. This drug is an inhibitor of the so-called RNA polymerase, which is an enzyme of the virus that makes copies of its genome. “It is a generic antiviral that has been used against other coronaviruses, it has also been tested against Ebola and it is now starting to be tested against SARS-CoV-2,” explains López-Goñi.
Favipiravir is another inhibitor of that polymerase that is also being used in clinical trials. Protease inhibitors, which are enzymes that play a role in the virus’s multiplication cycle when it is inside the cell, also show promise. The combination of ritonavir and lopinavir, which is commonly used against HIV, is being pursued. Lopinavir inhibits these virus enzymes, while ritonavir acts as a protector for lopinavir because it breaks down very quickly.
The mentioned compounds are combined with other anti-inflammatory or virus inhibitory substances, such as interferon, as well as with antibiotics (to treat or prevent secondary infections by bacteria) and cytokine inhibitors.
4- Promising vaccines, but with patience People who have had an infection are protected -immunized- against the pathogen in question. This statement applies to many viruses, but cannot yet be 100% certain for the new coronavirus. “It is most likely, but there are no definitive data,” says López-Goñi. “Experiments on infected macaques show protection against a second infection, but in humans we are not yet in a position to be able to state this.” If confirmed, it will be necessary to determine how long this immunization lasts against new exposures to the virus. The greater the immunity of the population, the second wave of the virus will be, at least in theory, smoother.
The desired vaccine can contribute decisively to this population protection. There are already more than 40 prototypes under study, but none of them are expected to be available in a year or a year and a half. There is an aspect of the virus that leads us to think that the development of an effective vaccine is going to be feasible: it is a pathogen that mutates less than others, such as the human immunodeficiency virus (HIV) or even the flu virus, to the one that has to make a new vaccine every season. Sanz warns of the importance of making the population aware of the usefulness and good use of these preventive treatments. “We have an effective flu vaccine and many people don’t get it,” he laments.
When the Covid-19 pandemic is viewed in perspective, the lack of foresight and lessons not learned will surface again. “We are seeing that viruses are not slow to leave the local level and become global immediately,” says Macip. “Global action is required and I believe that the World Health Organization (WHO) should have a body dedicated to pandemics to coordinate all countries and establish very clear rules.” In the expert’s opinion, it cannot be that each nation decides on its own – and in many cases without adhering to scientific criteria – when to adopt measures such as confinement.
If some time ago there was talk of global health, now many scientists -Macip among them- prefer to refer to planetary health, “which includes not only the health of humans, but the health of the planet.” In this sense, he considers that “health problems are increasing due to interaction with the ecosystem.” For this reason, he believes that “in the same way that we work on coordinating climate change and global warming, there are a series of problems derived from microorganisms and from interaction with nature with which the discipline dedicated to planetary health ”.
Live animal markets such as Wuhan, the Chinese town where Covid-19 originated, have been around for a long time. The difference is that now “what was once a local problem constitutes a global problem”. Therefore, no one will doubt or consider exaggerated – or perhaps they will? – the adoption of preventive measures in the face of the next pandemic threat caused by a pathogen that can be a flu virus, a coronavirus, a totally new virus, a bacterium …