A new omicron subtype is causing experts headaches. The many mutations on the spike protein could make BA.2.75 even more contagious than previous corona virus variants.

While the summer wave, caused by the omicron subline BA.5, has Germany firmly in its grip, a new omicron variant comes into the focus of science: BA.2.75. Experts are worried about the many mutations in the spike protein – they could make the sub-variant even more contagious than other virus variants. What the appearance of the omicron subtype could mean for Germany and what is already known about BA.2.75.

Where does BA.2.75 come from and how common is the Corona variant?

BA.2.75 is likely a second-generation variant—a descendant of the omicron subline BA.2, Imperial College London virologist Tom Peacock wrote on Twitter. In 2021, the researcher was one of the first scientists to warn about the omicron variant because of its mutations in the spike protein and now advises monitoring the new subline more closely.

According to the World Health Organization (WHO), the omicron subvariant, nicknamed “Centaurus,” was first discovered in India in May. Since July 7, the variant has been closely monitored by the European Center for Disease Prevention and Control (ECDC). The WHO is also monitoring the new variant in omicron tracking. So far, only a few cases of the new variant have been detected worldwide, including in Germany. “The total number of known BA.2.75 cases is minimal. We are talking about 70 cases worldwide today,” said Ulrich Elling from the Institute for Molecular Biotechnology in Vienna to “ZDF”. However, the expert assumes that the number of unreported cases is likely to be much higher.

Why are experts concerned about the omicron subvariant BA.2.75?

“BA.2.75 has a further eight mutations in addition to the 29 mutations that the BA.2 lineage already has in the spike protein. It can be assumed that such an abundance of new mutations have the properties to undermine the immune protection , will continue to strengthen,” said Ulrich Elling. That means: The “Centaurus” variant could evade the body’s immune response even better than other variants. This makes it easier to get infected despite vaccination and/or previous infection.

Is “Centaurus” more dangerous than the previous Omicron variants?

dr WHO’s Soumya Swaminathan told the Guardian that there weren’t enough samples from BA.2.75 to assess the severity. There is currently not enough data on the course of the disease or hospitalization to assess how dangerous the subtype is.

What does BA.2.75 mean for the adapted Omicron vaccines?

The American Food and Drug Administration (FDA) recommends vaccine manufacturers to rely on a vaccine against the omicron variants BA.4/5 for this winter. In Germany, the omicron subline BA.5 is also currently predominant. The European Medicines Agency has not yet decided which variant of the Omicron vaccine should be adapted to, as the star reported. What BA.2.75 means for an adapted vaccine cannot yet be estimated, says Elling. “As it stands, the evolution of the coronavirus is currently still faster than we can adapt the vaccines. It is very possible that the BA.5 vaccine provides insufficient protection against BA.2.75, the variants differ in eleven positions.”

Can corona tests recognize BA.2.75 worse than other variants?

There is speculation on social media that rapid tests and also PCR tests would not work with the omicron subvariant BA.2.75. Virologist Isabelle Eckerle wrote on Twitter: “It is very unlikely that BA.2.75 will not be detected by PCR”. However, it is already known that rapid tests are less reliable, especially after repeated infections.

Will BA.2.75 trigger a new wave in Germany?

“It’s hard to predict the impact of having so many mutations occurring together – it gives the virus a kind of ‘wildcard’ property where the sum of the parts could be worse than the parts individually,” virologist Tom Peacock told the Guardians. “Centaurus” is definitely a candidate for what could come after BA.5, concludes Peacock. However, it is difficult to predict how new variants will spread in the future. In addition to the virus itself, the immunity of the population also plays a role. For example, in India, where BA.2.75 was first discovered, there was no BA.1 wave, but there was a BA.2 wave. “If BA.2.75 is now spreading so rapidly in India, then it is reasonable to assume that BA.2.75 bypasses BA.2 immunity like BA.5 bypasses BA.1 immunity. In this case, there is also rapid international spread to be expected,” explains Ulrich Elling, looking at South Africa and Portugal, where there was a BA.1 wave and later many cases with BA.5. So far, there is too little data on BA.2.75 to know exactly how the new omicron variant will affect the infection process in Germany.

Sources: WHO,Guardian, ZDF, Twitter 1, Twitter 2, ECDC