There is a new strain of the Ómicron variant of the SARS-CoV-2 virus that is especially known to the scientific community. This sub-variant of the virus, named BA.2.75, was first detected in India in early May and is present in at least ten other countries, including the UK, US, Germany, Canada and Australia.
Although “it is not yet possible to understand the clinical impact” of the new variant, since it has recently emerged, it is “perhaps more contagious” than the strains of the virus that have been identified so far, notes Thiago Correia, professor. International Public Health at the Institute of Hygiene and Tropical Medicine of the University of Nova de Lisbon (IHMT-UNL). He adds that Centaurus, as it has been nicknamed, represents “many more mutations” compared to BA.5, the sub-variant that caused the latest wave of infections in Portugal.
On the other hand, the specialist says, “there is no evidence that it is associated with a more severe infection.” If so, then the “scheme” that the Ómicron variant suggests is confirmed with “increasingly transmissible” strains and an increased risk of re-infection, but no clinical consequences and no hospitalizations.
The specialist emphasizes that new strains and mutations of the virus are detected in the laboratory almost weekly. However, he acknowledges that BA.2.75 deserves special attention, especially as it has been identified in countries that do not share common borders. “There is no geographic proximity. That alone is of interest.”
On July 7, the European Center for Disease Prevention and Control (ECDC) classified BA.2.75 as an “under surveillance variant”. The World Health Organization is also monitoring the new strain, although it noted that there are not enough samples yet to assess its severity.
Manuel Carmo Gómez, an epidemiologist and professor in the Faculty of Sciences at the University of Lisbon, emphasizes that “there is currently no evidence” that BA.2.75 is associated with serious illness and an increased risk of hospitalization. It was classified as “important as it has a set of relevant mutations common to BA.2”, which became dominant in Portugal in March of this year, “and other new ones”.
Sub-options will continue to appear. Until there is a “new epidemic wave”
Although it has been found in several countries, BA.2.75 “does not play a very important role in Europe,” the epidemiologist emphasizes, adding that he is not aware of any cases in Portugal. However, he expects that the Ómicron variant of SARS-CoV-2 to which this new lineage belongs “continues to evolve in terms of more sub-variants with the ability to evade antibodies” provided by vaccination and infection. myself.
And among these new options, “it is likely that there will be one that will elude all the immunity that people have and cause a new wave of the epidemic,” Manuel Carmo Gomes also foresees. “We just don’t know when it will happen and how serious the situation will be at that moment.”
In view of this, it is necessary to ensure that the population most at risk, namely the elderly, immunocompromised patients and healthcare workers, continue to be “protected” by vaccines, the epidemiologist defends.
Thiago Correia also emphasizes that new variants and strains of the virus “will continue to emerge.” “Most importantly” is to understand the impact of these findings on the vaccinated population and accordingly “evaluate whether vaccination protocols should be changed and/or other vaccine approaches should be adopted.”
“These debates will continue in cycles,” he says, noting that “we are going backwards.” “It means living with the virus and understanding how it changes and the impact of these mutations on the health of the population.”
Infections and deaths with a “declining” trend in Portugal
In Portugal, the BA.5 strain of the Ómicron virus remains dominant, which appeared in the country in mid-May and “is perhaps the most dangerous strain of all, as it has an extraordinary ability to evade antibodies.” At the end of June, it accounted for 96% of infections, explains Manuel Carmo Gomes, adding other data on the epidemiological situation in Portugal.
He points out that cases of infection have a “decreasing trend” after reaching a peak on May 20, when 27,500 cases were reported. This drop is happening “in all regions of the country” and “spreads across all ages”, which “leads us to believe that the number of infections will continue to decline in the coming days.” The average number of cases per day is currently 7650.
The number of deaths is also on a downward trend, with an average of 17 deaths per day in Portugal. In late May, early June, when there was the peak of infections, there were an average of 40 deaths per day. The US and countries such as France, the UK and Germany are seeing a “worrisome” increase in infections and hospitalizations, mostly related to the BA.5 lineage, the epidemiologist describes. “Having passed through Portugal, the BA.5 is now invading the US and Europe.”
