“Centaurs”, new strain of Covid-19: It is “highly transmissible” but there is “no evidence” that it causes severe disease

There is a new strain of the Ómicron variant of the SARS-CoV-2 virus that the scientific community is particularly aware of. A sub-variant of the virus, named BA.2.75, was first detected in India in early May and is present in at least ten countries, including the United Kingdom, the United States, Germany, Canada and Australia.

Professor Thiago Correa points out that while it is “not yet possible to understand the clinical impact” of the new variant, its recent appearance means it is “more transmissible” than strains of the virus detected so far. International Public Health at the Institute of Hygiene and Tropical Medicine of the Universidade Nova de Lisboa (IHMT-UNL). Nicknamed “Centaurus”, it presents “multiple mutations” compared to the subtype BA.5 that last caused infections in Portugal.

On the other hand, the expert says, “there is no evidence that it is associated with a more severe infection”. If so, the Ómicron variant hypothesized “pattern” was confirmed, with “highly transmissible” strains and a higher risk of relapse, but without consequences from a clinical point of view and hospitalization.

The expert insists that new strains and mutations of the virus are being discovered in the laboratory at an almost weekly rate. However, BA.2.75 acknowledges that it deserves particular attention, especially as it has been identified in countries that do not share borders. “There’s no geographic continuity. That’s the only thing of interest.”

The European Center for Disease Prevention and Control (ECDC) classified BA.2.75 as a “variant under surveillance” on 7 July. The World Health Organization is also monitoring the new strain, although it has noted that there are not yet enough samples to assess its severity.

Manuel Carmo Gómez, an epidemiologist and professor at the Faculty of Sciences of the University of Lisbon, reinforces that “there is currently no evidence” that BA.2.75 is associated with a higher risk of serious illness and hospitalization. It is “important because it has a set of related mutations common to BA.2”, which dominated Portugal in March this year, “and new ones”.

Subvariants will continue to emerge. Until a “new pandemic wave” happens

Although it is detected in many countries, BA.2.75 “does not play a very important role in Europe”, the epidemiologist emphasizes, adding that he is not aware of cases in Portugal. However, he expects that the Ómicron variant of this new lineage of SARS-CoV-2 virus “continues to evolve in the sense of multiple subtypes capable of evading antibodies” presented by vaccination and infection. himself.

And among these new variants, Manuel Garmo Gómez expects that “one may emerge that escapes all the immunity that people have and causes a new epidemic wave.” “We don’t know when that will happen or how serious the situation will be at that point.”

With that in mind, it’s important to ensure that high-risk populations — such as the elderly, immunocompromised patients and healthcare professionals — continue to be “protected” by vaccines, the epidemiologist defends.

Diego Correa also stresses that new variants and strains of the virus “continually appear”. “The most important thing” is to understand the impact of these findings on vaccinated populations and, accordingly, “assess whether vaccination protocols should be changed and/or other approaches to vaccines should be pursued”.

“This discussion will continue cyclically,” he says, “and we go back and forth.” “This means living with the virus and understanding how it mutates, as well as the impact of these mutations on the health status of the population.”

Infections and mortality with a “declining” trend in Portugal

In Portugal, the BA.5 strain of the Ómicron variant of the virus dominates, which emerged in the country in mid-May and “may be the most dangerous strain of all because it has an extraordinary ability to evade antibodies”. At the end of June, it accounted for 96% of infections, explains Manuel Garmo Gómez, adding other data on the epidemiological situation in Portugal.

He points out that infection cases are on a “declining trend” after peaking on May 20 with 27,500 recorded cases. The decline is happening “in all parts of the country” and is “variable across all age groups”, which “gives hope that infections will continue to decline in the coming days”. An average of 7,650 people are infected per day.

The number of deaths also shows a “declining” trend, with Portugal averaging 17 deaths per day. In late May and early June, when the epidemic peaked, there was an average of 40 deaths per day. In the United States, as well as in countries such as France, the United Kingdom and Germany, there has been an “alarming” increase in infections and hospitalizations, mainly related to the BA.5 inheritance, the epidemiologist describes. “After passing through Portugal, BA.5 now invades America and Europe.”