What is the difference between the BA.5 subvariant and the Centaurus?

(CNN Spanish) — The covid-19 virus is spreading again in the world, mutating and causing the appearance, one after another, of new subvariants in a matter of weeks, which has the world’s health experts on edge as they are increasingly contagious and better able to circumvent immunity from antibodies produced by both natural infection and vaccines.

The most recent version of this mutation are the omicron subvariants BA.5 and BA.2.75, the latter better known as Centaurus, but what is the difference between the two?

Increasingly contagious subvariants capable of circumventing immunity

On the one hand, BA.5 is currently the dominant variant in the world and is generating a new wave of infections: in the week ending July 2, the BA.5 subvariant caused almost 54% of covid-19 cases. 19 in the United States and together with BA.4 caused almost 70% of the cases in that country.

While Centaurus, detected in India and 12 other countries, is spreading rapidly for what the World Health Organization has classified as variant of concern under monitoringwell it has eight mutations new on the spike.

Although not much is yet known about BA.2.75 or Centaurus, the main difference with BA.5 could be found precisely in the number of mutations in the spike, which is the crown-shaped structure that covers the surface of the virus and is adheres to human cells in order to infect them, according to the Dr. Soumya Swaminathan, Chief Scientist of the World Health Organization (WHO).

The subvariant of omicron BA.5 is already worrying in itself because it is more contagious than the original omicron variant, which was already much more transmissible than the delta and this, in turn, than the previous ones.

But Centaurus could be even more contagious than BA.5 and, according to scientiststhe eight additional mutations that it presents in the spike could make “immune evasion worse than what we are seeing now”.

Swaminathan, for his part, has said it is too early to know whether BA.2.75 has additional immune-evading properties or is more serious clinically. “We don’t know, so we have to wait and see.”

Although the chief scientist of the WHO agrees with the experts that each new variant “will be more transmissible and immunoevasive.”

“A higher number of infected will translate into higher hospitalizations and illnesses. All countries must have a data-driven plan to respond quickly to changing situations,” he added in a tweet.

With information from Dr. Elmer Huerta, Eliza Mackintosh, Maggie Fox