More than two years after the start of the pandemic and after the ómicron scare and the subsequent goodbye to the mask indoors, the coronavirus is once again a topic of conversation due to its increasing incidence and, above all, due to the numerous cases of reinfections (the vast majority with mild symptoms) in patients with two or three doses of vaccine and who had already had the disease on one or more occasions. This new increase in cases, baptized in many media as the seventh or eighth wave, has some characteristics of its own that distinguish it from others and aspects that are causing controversy among experts. These are some of the keys:
The new increase in cases is due to two subvariants of omicron called BA.4 and BA.5. Like omicron, they were detected for the first time in South Africa, in April. There is still much to investigate but it is known that they are extraordinarily transmittable, as evidenced by the fact that they are becoming dominant in dozens of countries in a few weeks, including Spain. How do you explain to LD the immunologist Matilde Canellesit would be more correct to call them variants and not sub-variants of ómicron because “they have varied greatly with respect” to ómicron and in turn from the original Wuhan variant.
The microbiologist and disseminator Ignacio Lopez Goni highlights, in statements to Onda Vasca, how “the circulation of the virus is very large at the moment” and how SARS Cov 2 evolves “towards more transmissible forms”. The Deputy Minister of Health of the Community of Madrid has renamed these new lineages of the virus with the qualification of covid-22 due to the fact that “the current coronavirus is very different from the original”. “It is a different disease”, caused by a different virus, “with mutations different from the original” and with a “different clinical result”, he highlights in an interview in Medical Writing.
Why do we get reinfected?
Perhaps the most striking aspect of this new wave of coronavirus is the frequency of reinfections. The differences of BA.4 and BA.5 Regarding the original strain and subsequent variants, they are what, according to Matilde Cañelles, are causing many people who until now had avoided the virus, or had been infected, to become infected again. Cañelles also recalls that the coronavirus is not a seasonal virus like the flu and “it is continually trying to infect, whenever it finds a hole it attacks us” and “he has found it by way of mutating”.
The epidemiologist and professor at the University of Oviedo Peter Arches points to LD that now three reasons are combined that explain the increase in reinfections. On the one hand, there are the changes in the characteristics of the virus: “The two new lineages are a little more transmissible and better evade the protection conferred by the vaccine.” On the other hand, regarding the exposure of the population, “now we are leading a normal life” and “the more contact, the more likely it is to be infected.” Lastly, “the immune status of the population” must be taken into account. Arcos considers it relevant that, for most, several months have elapsed since the third dose, so the short-term protection provided by the antibodies has diminished. In addition, studies cited by the journal Nature point out that the vaccine would be less effective in preventing the transmission of coronaviruses before BA.4 and BA.5, and these new lineages would also be capable of infect people who have been infected with omicron.
López Goñi highlights that SARS CoV2 “behaves as coronaviruses behave”, alluding to the other circulating coronaviruses responsible for mild colds: “One can be reinfected with colds“. It does emphasize that, although the two new lineages would be more capable of reinfecting, the cellular immunity provided by the vaccine and by the previous disease would continue to be activated to “protect us from severe forms”. Arcos maintains the same: although the vaccines “They defend us less, in the short term, from mild disease” and in addition “they work less well with these variants”, the lymphocytes continue to protect us from severe disease.
More transmissible and less serious?
Spain, where the BA.4 and BA.5 lineages have a prevalence of between 19.2 and 76.3%, depending on the territory, is a few steps behind other countries, which allows us to guess what this new outbreak of the disease. As López Goñi points out, in South Africa, the country where it first appeared, the data does not point to a greater severity and in Portugal, which is ahead of Spain, the wave “seems to begin to descend”. However, the microbiologist insists that it is difficult to make comparisons between countries while Cañelles asks for caution and wait for the studies to be carried out.
At the moment, Spain is experiencing, in tune with other European countries, a rise in hospital occupancy. It is at 8.3%, on the rise but very far from other moments of the pandemic. Those admitted are more than 10,000, figures comparable to mid-February, when the omicron wave descended. From Health, and from other regions, the recommendation to the vulnerable (immunocompromised and people over 65 years of age, among others) to use the mask indoors has been emphasized.
“Thanks to the level of immune protection of the population, most cases are asymptomaticZapatero points out. López Goñi, meanwhile, points out that although in principle these lineages are not associated with greater severity, “the more cases” there are, the more likely it is that it affects “the most vulnerable people.” Arcos affirms that these new variants “are much less pathogenic and virulent“, that even “there are only symptoms in barely 30% of those infected” and that, in general, “very mild symptoms” occur. He also points out that currently “practically almost the entire population has had contact” with SARS Cov 2, understanding exposure to the virus by contact. Fortunately, he points out, in many cases “the defense system” of the human body “reacts quickly and kills the virus before it can enter the body” and does not even reach produce the infection.
The professor also warns that the photos and images of hospital “saturation” just when the holidays begin “have nothing to do with covid” but rather with a lack of medical resources and poor management. Y points to the role of the media in “the social perception of risk” around the pandemic, which depends largely, in his opinion, on the “huge amount of information and how it is focused”.
While waiting for the possible fourth dose of the vaccine, the experts agree that the focus should be on this moment of the pandemic “in the most vulnerable people and in the patient who can end up in the hospital”. López Goñi highlights how “the virus evolves at an enormous speed” and how “the pandemic is not over yet”. In this regard, Zapatero highlights that today, “thanks to the level of immune protection of the population, the majority of cases are asymptomatic”, and that “at the moment it mainly affects chronic patients or patients with previous pathologies, because it exacerbates their disease”. For the unvaccinated, on the other hand, these new strains they are just as damaging as the original, which is why he warns that you have to be “careful with absolute tranquility”.
Some virologists such as the German Christian Drosten, this new wave has led him to affirm that the end of the pandemic, full “normality”, will take a little longer to arrive due to the impact they foresee, again, in the number of hospitalizations and deaths although they do agree that income and deaths they will be “much less than in 2021”. They also draw attention to the consequences of persistent covid, the consequences of different intensity that affect a small part of those infected. In any case, that there are new waves is something that was already warned after the impact of omicron and when talk began of a “beginning of the end” of the pandemic.
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