The number of infections in Indian megacities is exploding. Researchers fear that this is due to a new corona mutation that has now reached Europe. How dangerous is B.1.617?
India is home to more than a billion people. So far, the country has coped quite well with the corona crisis – even though millions of people live in megacities under precarious conditions and in cramped spaces. But since this week, infection rates have exploded in New Delhi and Mumbai, the country’s two largest cities: On Thursday, 200,000 people contracted the coronavirus – the most in a single day since the pandemic broke out.
Recorded corona cases have been increasing stronger and faster than ever in the country for weeks – while at the same time hundreds of thousands of people have been bathing in the holy Ganges River as part of the world’s largest religious festival, often without masks or distance. The cause of the high number of new infections could also be a mutation of the coronavirus.
This is indicated by the results of laboratory tests in the state of Maharashtra. In more than 60 percent of the genome sequencing performed, researchers found the novel B.1.617 variant. It is considered a dangerous combination of the virus mutants from Great Britain and South Africa.
Mutations in coronavirus are nothing unusual, but some are far more dangerous than the original virus type. To spot new variants, laboratories would need to regularly sequence positive corona samples. But researchers cannot immediately know exactly how the virus variants work and whether they are more infectious or deadly.
That’s why experts are unsure whether B.1.617 is really responsible for the high infection numbers in India. “The number of samples is still very small – so we cannot directly conclude that the increase is caused by the variant,” Sujeet Kumar Singh, director of the state health department told The India Express.
The new variant arrived in the United Kingdom this week. By midweek, the government’s Medical Information Service (PHE) reported 77 cases. The B.1,617 variant is a combination of several mutations, the statement said.
There, people are now more concerned than in India. “The new variant could be even more difficult to control with vaccines than the variants that first appeared in Brazil and South Africa,” British physician Paul Hunter of the University of East Anglia told The Guardian newspaper. This is because at least two dangerous mutations are very likely to work together in B.1.617.
The variants that first appeared in South Africa and Brazil also carry several potentially problematic mutations. One of them, known as E484K, ensures that neutralizing antibodies formed by vaccines no longer bind as stably to the virus.
German virologists are more cautious with their assessment than their British colleagues. It is not yet possible to assess the biological properties of the B.1.617 variant, Jörg Timm, director of the Institute of Virology at the University of Düsseldorf, as publoshed by derspiegel.de. “The mutations in the spike protein of B.1.617 are already known from other variants,” Timm said. It can be assumed that these can also “bypass” the immune defenses, he said.
In this case, the body reacts to the attack of the virus only with a delay or not at all with an immune response – among experts, this phenomenon is also called “viral escape” or “immune evasion.”
The spike proteins with which the viral envelope is studded, serve the virus to penetrate human cells. Mutations can improve the properties of this grappling hook, causing it to become more likely to infect. In addition, the spikes are the prominent feature of the virus by which the human immune system recognizes the attacker; mutations that obscure this feature can make the immune defense more difficult.
“I would currently assume that the effect is comparable to the variants from South Africa and Brazil,” says virologist Timm. Accordingly, new infections could well occur in the case of partial immunity, where antibodies are already present. So people who have only been vaccinated once or have only had mild covid disease could also become infected. “However, severe courses with existing immunity or after vaccination are probably rather rare,” says Timm.
- source: derspiegel.de/picture: pixabay.com
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