Although the SARS-CoV-2 coronavirus will not go away, vaccination will allow it to become a seasonal virus with less impact.

Puerta del Sol in Madrid during the Covid-19 pandemic.

The pandemic will end, and for this to happen it will not be necessary for the new coronavirus to disappear from the planet. The scientific community agrees that SARS-CoV-2 will become an endemic respiratory virus, as already is, for example, the seasonal flu.

“We will probably see an evolution of the virus,” he says. Beatriz Mothe, specialist in the infectious diseases service of the Germans Trias i Pujol Hospital in Badalona, ​​near Barcelona. “The virus will adapt,” he predicts.

The reasons are various, but they can be summarized in two: vaccination will not completely eliminate SARS-CoV-2 and the virus will probably evolve to continue to spread in a milder way, without killing the host.

On the one hand, vaccines prevent the most serious forms of COVID-19, but they have not yet shown that they are capable of nip virus transmission or how long immunity will last caused by the vaccine.

For now, throughout history vaccination programs have succeeded in completely ending two diseases: smallpox and rinderpest, It did not affect humans, but caused a major food shortage.

On the other hand, viruses need a host like humans to replicate and survive. Therefore, its evolutionary logic It is not to kill the host, but to continue infecting to reproduce in it.

“This virus has come to stay, we are going to continue living with it,” he says. Sonia Zúñiga, virologist at the National Center for Biotechnology of the Higher Council for Scientific Research (CNB-CSIC). Some of the factors that will influence the conversion of the new coronavirus into an old acquaintance are its velocity of propagation and the vaccination rate.

One newspaper article in the magazine Nature He added other arguments that support the thesis that the coronavirus will not disappear from our lives. Some of the factors that can strengthen blood circulation SARS-CoV-2 on the planet are the reluctance of some people to get vaccinated and a possible change in behavior of those already vaccinated when they feel safer.

That is why it is important that After getting vaccinated, we continue to maintain protective measures: mask, hygiene, ventilation and limitation of social interactions.

The end of the acute phase of the pandemic will come with the generalization of vaccination, which should be extended to the whole world. Studies estimate that this will not happen until 2024 by the uneven distribution of doses, according to the Center for Innovation in Global Health at Duke University (USA).

From then on, according to the hypothesis of a projection published in early 2021 in the magazine Science, the virus would circulate less and cause less severe symptoms.

The authors of this study resemble the SARS-CoV-2 four other coronaviruses, ‘first cousins’ of hers, who cause the common cold; and differentiate it from its predecessors SARS-CoV Y MERS-CoV, which emerged in 2002 and 2012.

The post-pandemic phase will be influenced by factors such as the reinfection, the seasonality and the competition with other viruses to impose on them, according to another job published in late 2020, also in Science.

Survive at all costs

The appearance of new variants of the SARS-CoV-2 can complicate the picture. Although it mutates less than other viruses, such as influenza or HIV, new variants have emerged that are more contagious, but not more deadly. Their mutations they focus on the protein S in their crown to better latch onto human cells and continue to infect.

“In some way, we are giving the virus opportunities to acquire new mutations and evolutionary advantages, as new variants that are transmitted better and are capable of evading the immune response “, he says Francisco Díez, researcher at the National Microbiology Center of the Carlos III Health Institute (CNM-ISCIII).

For example, the D614G mutation appeared in January 2020 and within half a year it became the dominant variant worldwide, replacing the original virus that was detected in China, according to the World Health Organization (WHO). This new version of the virus was more infectious and transmittable than the old one. Now all current variants come from this one.

One of them is VOC-202012/01, which adds the N501Y mutation, first identified in south-east England, which, in less than two weeks, had already spread throughout the United Kingdom, also according to the WHO.

Or in South Africa where viral variant 501Y.V2, which includes additional mutations in crown protein S, such as E484K and K417N, has been associated with an increased viral load, which would translate into a much higher transmission capacity, says the WHO.

“These are the weapons that the virus has to survive: modify your genome”, Explains Díez, who has studied the genetic diversity of the new coronavirus in Spain since the beginning of the pandemic.

“If the virus continues along this line, it is very difficult to eliminate, as happens with the influenza virus,” Zúñiga emphasizes. Because, We hope that he lives with us and the serious cases that he causes are less and less”.

Due, beyond vaccines, which may have to be updated from time to time, treatments will also be key to treating the most serious cases, which need special attention.