As more than 1.8 million people have received the COVID-19 vaccine worldwide, according to the Bloomberg Vaccine Tracker. There is now a new strain coronavirus outbreak in several European countries.
When a scientist analyzes the genetic material of the coronavirus that circulates among patients in Brazil or Europe, for example, what appears is a strain of virus different from that seen in Wuhan, China, in December 2019. All because viruses are crackers in undergo rapid mutations. In the case of Sars-Cov-2, for example, researchers noticed that, since the first time the virus was identified, almost a year ago, a few thousand mutations have already appeared – 4 thousand of them in such spike proteins alone. Only a minority, however, was able to change the structure of the virus significantly.
“Mutations are to be expected and are a natural part of evolution. Many thousands of mutations have already emerged, and the vast majority have no effect on the virus, but it can be useful in the task of monitoring outbreaks, ”explained Sharon Peacock, director of COG-UK (UK Genomic Consortium, Covid-19, UK) .
Until now, these mutations did not appear to pose much of a threat. But a new set of changes in the genetic code, which spawned a new strain (or strain) of coronavirus, gained worldwide attention, especially last weekend. Named B.1.1.7, it was identified in England, and appears to have acquired 17 mutations at once.
Researchers suggest that this package of virus changes appeared in the body of a patient with a weakened immune system. Since the body was unable to fight it, Sars-CoV-2 may have been incubated in this patient’s cells for a long time, incorporating a greater amount of changes. It is not yet known whether the mutation package appeared in a British patient or was imported from elsewhere, without being immediately identified by scientists.
The new version of the virus soon became of concern in Europe – and worldwide. The B.1.1.7 strain was first detected in September, and in November it caused 26% of London’s Covid-19 cases. Its advance was rapid and, until mid-December, the lineage was responsible for more than 60% of the cases registered in the English capital. British Prime Minister Boris Johnson even announced on Sunday (20) that the transmission rate of the new viral strain was already 70% higher than that of previous strains.
Faced with the new news, Holland and Italy opted to restrict flights from the United Kingdom, an initiative that was also soon adopted by neighboring countries. As of Monday afternoon, the list of nations that banned people from the United Kingdom had more than 40 names. Meanwhile, England has adopted stricter local restrictions, such as the return of the lockdown state.
In addition to the high rate of transmission of the new strain, something that has aroused the concern of countries is about the possible resistance of the virus to the vaccine. After all, is there a risk that approved or developing vaccine versions will not be effective in stopping modified Sars-CoV-2?
To try to answer questions like this, one must first understand the potential impact of mutations. In the case of the B.1.1.7 strain, there are some problems. The first is that, as we have seen, it has already become the version that most infects people in London – meaning that it can potentially “replace” other strains. The second is that it brought about changes in the structure of the virus. Sars-CoV-2 of this strain have differences in the protein spike – the “key” used by the coronavirus to open the cell door and invade them.
One of the mutations incorporated into the new strain, N501Y, targets an important part of the spike proteins, called the “receptor-binding domain”. This can be a problem, since, according to tests, viruses with this change can enter human cells more easily. By table, the variant would be more likely to multiply inside the organism, aggravating the case of an infected patient, and to spread among the population.
With more people immunized, either because they have already been infected or due to vaccination, it is common for the pathogen to end up incorporating changes that make it spread more or go unnoticed by the immune system. But, for now, this should not affect the immunizers available on the market. Health officials suggest that a package of mutations of this level, capable of affecting vaccination, would take years to be incorporated into Sars-CoV-2.
Of course, all this does not exclude the need for science to continue tracking Sars-CoV-2 mutations. Influenza viruses, which cause influenza, for example, are closely monitored by scientists from around the world every flu season. This allows for constant updates to the vaccines, which are offered annually. The same can happen with the immunizer for Covid-19, a disease with the potential to become seasonal. In addition, any changes in the virus may raise less concern if, within a year, we are able to vaccinate about 60% of the population and control the growing number of cases.
The scientific community treats the British government’s announcement that the new strain is 70% more transmissible. There are still unpublished surveys that indicate smaller numbers – while others suggest even higher figures. The fact is that there is still not enough evidence to establish whether the B.1.1.7 strain can replace other versions if it is introduced in a certain region.
Researchers point out that it is still not possible to say, also, if the greatest appearance of this strain is exclusively related to the virus, or if there was influence of the Europeans’ own behavior in these last months of the pandemic. With the relaxation of social isolation measures in certain areas, it is possible that versions that circulated there have “jumped” to areas where they did not appear so much before.
“This variant is strongly associated with places where we see increasing Covid-19 rates,” said Nick Loman, professor of microbial genomics and bioinformation at the University of Birmingham, in a statement. “It is a correlation, but we cannot say that it is causality. But there is remarkable growth in this variant, which is why we are concerned. She urgently needs monitoring and investigation ”.
There is also no data on variation in the mortality rate of Sars-CoV-2 – whether this mutation can make it more deadly – and whether antibodies from already infected patients may not protect against the new version of the virus. All of this proves that the list of questions to be answered by scientists is still extensive.
The United Kingdom was not the only country to register the new lineage. Denmark, Australia and the Netherlands have also reported cases – probably imported from England. In South Africa, scientists have detected a similar version of the virus, which shares some of the mutations. In mid-November, about 90% of the analyzed genetic sequencing samples had the modified pathogen.