How dangerous is the BF.7 variant?

At the beginning of December, China dropped its strict anti-corona measures. Since then, the virus has spread rapidly. According to unofficial estimates, almost 250 million people could have been infected in the first three weeks after the bans were lifted.

Last weekend, the country reported 60,000 corona deaths since the easing began. Experts consider this number to be an understatement. The British data processor Airfinity assumes that around 3.7 million people in China are newly infected with the virus every day – and around 21,000 people die from it every day. According to these estimates, almost 350,000 people have died since the beginning of December. According to the projection, the number of corona deaths could increase to 1.7 million by the end of April.

One subvariant is said to dominate the infection process in the Asian country: BF.7. What do we know about the mutant?

What is BF.7?

It is a subvariant of the currently dominant mutant BA.5 in Germany. It again has a mutation in the spike protein, through which the virus enters human (host) cells. According to the latest weekly report from the Robert Koch Institute, around 22 percent of the current infection rate in Germany can be attributed to BF.7.

As is often the case with the new subvariants, BF.7 is better able to evade the built-up immune protection through vaccination and/or infection, so people can (re)infect themselves more easily.

Where is BF.7 still common?

BF.7 was also discovered, for example, in India, the USA, France, Denmark and Belgium. But the wave of infections in these countries is harmless compared to the data from China. Nowhere were such high death rates reported.

What makes the Chinese situation different from other countries?
On the one hand, the country is comparatively densely and closely populated in its megacities. But the decisive zero-Covid strategy seems to play a more important role. For years, the authorities prevented the population from contact with the virus through lockdowns and other restrictions.

It was also not possible to build up immunity, even if it was often temporary. At the same time, the vaccination campaigns quickly came to a standstill, especially in the population groups that are considered to be particularly vulnerable under Corona. Most of them are not boosted and therefore not basic immunized. In addition, the vaccines produced and deployed in China are not of the same quality as Western mRNA vaccines – particularly with regard to the omicron variant.

This allows the virus to pass through the population fairly unchecked. And of course it also hits vulnerable groups who are practically defenseless at its mercy.

What does BF.7 mean to us?

So far, BF.7 has not been the dominant variant in Germany, although it must be said that testing is nowhere near as frequent in this country as it was during the peak phases of the pandemic. Apart from that, sequencing is also comparatively rare in Germany, i.e. the virus is examined for its genome. The subvariant BQ.1.1 is currently detected most frequently (26 percent). It seems to escape the immune protection of triple vaccinated particularly easily, also better than BF.7.

Against this background, the chief virologist at the Berlin Charité, Christian Drosten, characterized BF.7 as the “better case”. In an interview with “Zeit” he said in mid-November: “BF.7 would be the better case, this variant is very similar to BA.5, against which a large part of the population is already immune. There would then be a gentle winter wave.”

What other dangers are looming from China?

So BF.7 might not become a big problem for us. However, the situation in China must continue to be closely monitored. The World Health Organization (WHO) recently requested more information from China. WHO Director-General Tedros Adhanom Ghebreyesus welcomed the exchange and publication of the information on sickness and death numbers. They allowed a better understanding of the epidemiological situation, the WHO said in a statement. Tedros has requested that “this type of detailed information continues to be shared with us and the public,” the WHO said, promising support.

The fear: the emergence of new variants. The Bonn virologist Hendrick Streeck explained in an interview with the “Münchner Merkur”: “The Chinese are a very large people with around 1.5 billion.” If many of them were to become infected in the next few months, there could be renewed selection pressure on the virus, and this could result in mutations. Streeck: “You have to imagine it like this: In a relatively short time, many immune systems try to contain the virus – but the virus tries to escape it. This can lead to immune escape variants. This has already happened in many other parts of the world, as we have seen from the different variants.”