Virus variant Delta continues to rise in Germany

The coronavirus variant Delta discovered in India has significantly increased its share of new Sars-CoV-2 infections in Germany within a week.

According to the latest report from the Robert Koch Institute (RKI), at 6.2 per cent in calendar week 22 (May 31 to June 6), it is relatively rare. In the last week (week 21), the proportion of the delta variant in the samples tested, including late registration, was 3.7 per cent. Once a week, the RKI evaluates the proportion of reported virus variants that are classified as worrying.

With 86 percent of the samples tested, the alpha version (b.1.1.7, discovered in Great Britain) caused the majority of infections nationwide in the first week of June. However, their share is gradually declining. Other worrying versions Beta and Gamma still play only a subordinate role.

For Dortmund immunologist Carsten Watzl, a significant increase in the delta variant alone is not an indicator of an imminent fourth wave. “But we have to be careful not to escalate incidents through careless openings,” he writes on Twitter. Watzl estimates from small data collection that the proportion of delta variant in Germany is currently already over ten percent. But it is still low – compared to Great Britain for example.

The delta version is much more contagious

In the past few weeks, it remains to be seen how quickly the delta variant can worsen the infection situation despite an advanced vaccination campaign. In April, the first cases of this mutant were detected in England, which is said to be mainly due to travelers from India. They arrived before the British government placed India on the so-called “Red List” with a mandatory 10-day hotel quarantine. In early May, when the British public health authority classified the mutant as a “severe form of concern”, Delta was already making up about a quarter of cases.

In mid-May this mutant overtook the alpha version which was still dominant in Germany. Only two weeks later there were almost only delta cases. The seven day event in Great Britain is currently back at around 70 – previously it was around 20 for weeks. The incidence has therefore increased rapidly, even though more than 57 percent of adults in Great Britain are now fully vaccinated.

Unfortunately, the delta variant is 60 percent more infectious than the alpha mutant, tweeted scientist Watzl. In addition, they may evade better immune defenses. “As a result, people’s antibodies are barely capable of neutralizing the delta variant after the first vaccination.” On the other hand, fully vaccinated people are well protected from it.

The delta version should be taken seriously because it can be transferred more quickly, says Berlin physicist Dirk Brockmann of the Institute of Biology at Humboldt University. One should consider that values ​​in the low percentage range nationwide mostly go back to local outbreaks, he said on rbb-inforadio. The alpha version also started out so small, but then prevailed. In his opinion, the same would happen with Delta mutants.

Vigilant confidence thanks to vaccination

The number of cases in Germany is falling at the moment. “But you have to be on your radar that even this version may prevail.” For example, the UK government has postponed planned easing for parts of England and Scotland for several weeks.

However, immunologist Watzl is confident that the delta version probably won’t lead to a new wave in Germany this summer. But this is also due to the behavior of the returnees and tourists from abroad, he emphasized. It is also important to fully vaccinate as many people as possible in the summer. In Scotland, the delta variant has spread especially among the younger generation. “That’s why discussions about immunization of children and adolescents will be important.”

With a good vaccination rate of over 80 percent by autumn, Watzl is confident that Germany will get through the winter well, despite the dominant delta variant at the time.