The number of officially confirmed corona cases in Germany has continued to fall significantly in the past week.

The nationwide seven-day incidence has fallen by 30 percent compared to the previous week, reports the Robert Koch Institute (RKI) in its Covid 19 weekly report on Thursday evening.

"At the beginning of the new year, the downward trend continued, with a sharp fall in the number of cases in the first few weeks of the year," writes the RKI.

The incidence alone is now considered to be of little significance, but the trend is confirmed by other indicators.

According to the RKI, the number of patients who have been treated in hospital with a severe acute respiratory infection and a Covid 19 diagnosis has been falling for weeks.

In addition, the occupancy of the intensive care units with Sars-CoV-2 infected people continues to decrease.

Increases are observed in certain virus variants in Germany.

Among other things, the proportion of the omicron subline XBB.1.5 is growing.

The RKI reports this with a view to the most recent evaluation of samples from the week before last.

XBB.1.5 is already more widespread in the USA, for example.

The level in this country is still relatively low at almost five percent.

In the past week, the RKI had spoken of a good two percent share.

According to the analysis, more severe courses of the disease in this context are not known to date.

Three years of Corona in Germany

The first evidence of a corona infection in Germany was announced in Bavaria on January 27, 2020.

As of January 25, 2023, more than 37.7 million laboratory-confirmed infections were reported to the RKI.

There are countless more under the radar.

The number of people who died in this connection is now over 165,000.

New vaccines adapted to the omicron variant have been available for several months.

According to the recommendation of the Standing Vaccination Commission (Stiko), certain groups, such as people over 60, should receive a second booster vaccination to improve protection against a severe course of the disease.

However, the vaccination rates for second boosters have so far been low and vary greatly from region to region.

"I was disappointed at times.

I would have wished for greater acceptance of the recommended vaccinations," says Stiko boss Thomas Mertens.

Despite vaccination gaps, the bottom line is that experts speak of good basic immunity.

Virologist Christian Drosten recently pointed out in the "Coronavirus Update" podcast that the virus is now much easier to transmit than at the beginning of the pandemic.

One of the main reasons for the relative calm at the moment is the population immunity, which is curbing the spread of the pathogen.

Seasonal corona waves still unlikely

Research will keep an eye on how long this protection lasts.

"We will have to monitor this very closely in the future when new variants appear, for example on the basis of hospital admissions," said Leif Erik Sander, Director of the Clinic for Infectious Diseases at the Berlin Charité Some researchers see reason for optimism because there are data for longer periods of time.The immunologist Andreas Radbruch, for example, assumes sustained immunity based on the data on the first Sars virus (2002/03).

Some doctors express the idea that in the future, vaccination against corona should always be carried out in autumn, as before the flu epidemic.

However, Sander is skeptical as to whether the coming corona waves will fall as predictably in the winter months as is typically the case with flu: "It will probably be a while before we really have synchronous, strictly seasonal corona waves." Vaccinations for certain vulnerable groups may be conceivable every one to two years.

One must assume that primarily certain risk groups should receive further booster vaccinations in the future, according to the Stiko.

It is not yet possible to scientifically name the exact time interval, but a one-year interval might be reasonable.

"The protection against serious illness through vaccination is very good, but avoiding reinfection is only possible for a short period of time with vaccination," said Mertens.

For people without risk of severe Covid-19, he therefore currently does not expect the vaccination recommendation to be expanded.

For the Charité infectiologist Sander, it is conceivable that younger people with a healthy immune system may only need a refresher every few years - if the virus itself does not provide the refresher with repeated infections.

Further developed vaccines can also be expected in the future.