Guide for the seventh wave of COVID: "I don't know if we will all get it, but almost"

Guide for the seventh wave of COVID: "I don't know if we will all get it, but almost"

The third summer of the pandemic has begun, although this will be a very normal vacation for most people. The collapse that worries travelers will be more in airports, not in hospitals. The waves capable of ruining your plans will be the heat waves. The great music festivals and Sanfermines are back. However, now and always, the coronavirus is still here. After several false alarms so far this year, a clear seventh wave has arrived and has given back to COVID-19 part of the prominence lost in recent months. Once again we want to know what SARS-CoV-2 has in store for us. For the first time, it hits us in the absence of prophylactic measures.

"There is a lot of transmission. As much or more than in the middle of the sixth wave," FISABIO researcher Salvador Peiró assures "I don't know if we will all get infected, but almost." He considers that the elimination of social distancing measures and the return of crowds will make the seventh wave a "very fast" wave that "will begin to decline in a few weeks due to exhaustion of susceptibles." In fact, the latest data reported this Friday show a decrease in incidence in people over 60 and in hospitalizations for the first time since the beginning of June.

At the moment, admissions to the ICU remain at a minimum. "For the existing transmission there is very little hospitalization and fewer ICUs," reassures Peiró, who thinks that the latter have been "somewhat decoupled" from the rest of admissions. People hospitalized for COVID-19 "are on average less severe, with less pneumonia, fewer pictures of pulmonary inflammation, and less need for ventilators." However, he recalls that "many infections end up giving a lot of hospitalization." This new push of infections has its own characteristics:

Comparing data, countries and waves has not been easy – or even possible – since the start of the pandemic. And yet it is becoming less and less easy. Added to the lack of data is the fact that high incidences have less and less impact on the health system, and that incidental hospitalizations – those in which the main reason for admission is not COVID-19 – represent a higher percentage. Measuring them is not easy, but trivializing them is a mistake.

Peiró explains that, in the Valencian hospitals for which he has data, incidental hospitalizations represent "between 40 and 60%" of the total for a couple of months. He assures that the fact that some surgeries are no longer suspended despite the positive in SARS-CoV-2 has increased that percentage.

These numbers are good news, but they also need nuance. Peiró clarifies that incidental hospitalizations are something "very subjective" due to the lack of a clear definition. He also remembers that the coronavirus "always bothers", even if it is not the main character. "It occupies many beds due to isolation and COVID areas, blocks the admission of other patients, complicates organizational aspects. Even the mildest cases complicate daily activity in primary care and in the emergency room." This without forgetting that SARS-CoV-2 can worsen the condition of a vulnerable person even if this was not the reason for their admission.

Although the lack of incidence data has been criticized, Peiró believes that what is missing is the information that really matters to adopt or not measures. "We already have an idea of ​​the transmission even though we don't have the exact data, but it is surprising that we report data every three days of very little value for decision-making and we barely know about the severity of the cases, their age or mortality —which also has a lot of incidental—, and that are key to decision-making".

Until the end of 2021, the variants of SARS-CoV-2 made our lives bitter, but at least it was easy to locate ourselves. "British variant" -later alpha-, beta, delta... And then came omicron. This last lineage made communication difficult by subdividing itself into BA.1, BA.2, BA.4, BA.5, BA.2.75… And the public stopped paying attention.

The World Health Organization explains that the original omicron was a variant of concern (VOC), so all lineages descended from this are also. However, there is a question as to whether new Greek letters or names should be used, even if it is to make communication easier for the public.

"I don't think it's still necessary to give it a new Greek letter, because phylogenetic trees, although they form their own group because they have differences, are still within the great group of omicrons," explains the virologist at the National Center for Microbiology María Churches. "I think they can still be omicrons, and indeed they are."

At the moment, in Spain the variants that circulate the most are the BA.2 –in decline– and the BA.4 and BA.5 –depending on the autonomous community–. Iglesias explains that these are the lineages to pay attention to, but "without any special alarm" on the part of the public. "As always, those of us who are dedicated to surveillance have to continue characterizing and monitoring the lineages that circulate as our normal routine, in case something very relevant comes up, but for now the vaccines remain effective with severe cases," he says.

To this situation we must add the variant BA.2.75, which has received a lot of media attention despite the fact that it has hardly been found outside India for the time being and it is not clear that it can prevail over the dominant BA.5. The reason is almost comical: a Spanish tweeter came up with a catchy name"centaurus", capable of grabbing headlines.

Iglesias asks for calm and patience due to the lack of data around BA.2.75. "It has a spike with some impact that may be interesting to monitor, but we still have to see how it evolves at the level of transmission and circulation within the community." Spain, for the moment, has not seen this variant on its borders. "Centaurus", as was the case with other unofficial variant names such as "the devil", "deltacrón" and "delta plus", has marketing on its side, but it remains to be seen if it also achieves biological success.

In recent days, various media have baptized the BA.4 and BA.5 variants as "the most contagious viruses known to man". It is a title that, in one way or another, they already shared BA.2the original omicron and even delta. Is it possible that each new variant is more transmissible than the previous one? If new variants continue to emerge, will SARS-CoV-2 continue to break this record forever?

The origin of this misunderstanding lies in an article in which a researcher calculated that the R0 – the average number of cases produced by each infected person – was more than 18. "We have killed the R0 based on bad science," criticized the epidemiologist Adrián Aginagalde On twitter. One reason is that this famous number is used in populations with no prior immunity, making it difficult to apply in 2022 when most people have been vaccinated, infected, or both.

"Just because something has a 50% 'growth advantage' in a population doesn't mean it's 50% more 'transmissible,'" the Emory University biostatistician explained on Twitter. Natalie Dean. And the key: "Some or most of that advantage could come from immune evasion."

All viruses evolve alongside the immune systems of their hosts in an endless arms race. Each winning SARS-CoV-2 variant follows the same cycle: it increases in number, dominates the others, and finally begins its decline while being replaced by the next.

In this process, population immunity is one of the factors that play an important role. That is why the variants do not compete on equal terms: when a 'young' and new version appears, the previous one is already 'old', has accumulated negative mutations and fought against the immune systems of a large part of the population. The combat is not fair and the new version prevails. Actually, we don't know what would have happened if both had seen each other's faces at the same time during their youth.

As a result, it is not possible to conclude that each new variant is more contagious per se than the previous one, only that it has an advantage in a given time and context. Otherwise, in a few years the omega variant would be hundreds of times more contagious than omicron and the coronavirus would break, for the umpteenth time in a row, the record for the most contagious virus in history.

Epidemiologists, doctors, immunologists, and even engineers have been consulted throughout the pandemic about masks. We know that they work, but also that decisions on public health must be made in a sociopolitical context that goes beyond scientific articles, papers. Today masks are recommended indoors and in crowds, but could they become mandatory again in the middle of 2022?

"Masks have been the most accepted protective measure by Spaniards, less problematic and more consented to, perhaps because they are less invasive and expensive," explains the sociologist at the Complutense University of Madrid Igor Sádaba, citing data from 2020. He considers that "by not require so much effort" became very widespread, understood as a "possibility of self-protection and civic solidarity with others".

This, however, was in 2020. "The pandemic and the measures have caused extraordinary fatigue, exhaustion, mental and social fatigue. We were not used to this, which had never happened before and we have also normalized the virus and many people believe that these measures are not necessary no matter how highly recommended they may be," continues Sádaba. He considers that the "chaotic" rules of use have not helped the population understand the use of masks.

For this reason, the sociologist sees it difficult for the obligation to return in the remainder of the pandemic. "In my opinion, reintroduce the mask [obligatoria] It would be possible, but a very high risk situation would have to be seen, because otherwise we would live in the world of picaresque and exceptions, "he says. As long as the vaccines continue to work and keep the most vulnerable away from the ICU, it is unlikely that this scenario is reached.

Does this mean that we can forget about COVID-19? "There is a disconnect in the perception of the risk posed by COVID-19 between the scientific community, political leaders and the general public," said the WHO committee that has decided maintain the public health emergency of international concern. The pandemic is not over yet, but everyone hopes that it will soon give us vacations until the cold returns.

Source link