Arcturus coming – who needs a booster shot now

The new variant XBB.1.16, also known as Arcturus, has been spreading in India since February. It has been causing a rapid increase in the number of infections there for a few weeks. The World Health Organization (WHO) therefore put the variant on the list of variants to be observed (variants under monitoring) on ​​March 22nd. According to the current report of
WHO
it has already been proven in 21 countries worldwide.

XBB.1 lines on the rise in Germany

In Germany, only seven cases have been officially assigned to this variant. However, since only very few samples are tested for variants, the number is likely to be higher. The Robert Koch Institute is therefore assuming that all of the XBB.1 lines, including Arcturus, will increase in the coming weeks.

According to the weekly report, the share of the XBB.1 variant in Germany has increased in recent weeks and is now 67 percent. The previously dominant variants BA.5 and BA.2, on the other hand, have continued to decline:

• The
  Share of BA.5
  is only included
  16 percent
  .

• The
  Share of BA.2
  only with
  14 percent
  .

Virologist recommends vaccination according to Stiko recommendation regardless of Arcturus

Even if nobody in Germany wants to think about Corona anymore or thinks it is a danger, the pandemic is not over yet. The current weekly report of the RKI still states that unvaccinated people of all age groups have a significantly higher risk of a severe form of Covid-19 and vaccination is the best prevention to prevent a severe course of Covid-19.

“In principle, everyone should have been vaccinated against Sars-CoV-2 in accordance with the current Stiko recommendations

“Said the virologist Martin Stürmer when asked by FOCUS online. “If the scheme is still incomplete, a booster vaccination should be carried out independently of the currently circulating variants

‘ he recommends.

“However, it is currently not possible to estimate the extent to which further boosting reduces the probability of an infection with Arcturus

‘ Striker said. “But I would be more cautious here. Arcturus certainly has the potential to undermine our immune system, but then a boost with the current vaccines would probably not help much either, since they are responsible for the current basic immunity in the population

‘ he elaborates. It is therefore now important to continue to monitor the status of this basic immunity and to define target groups and distances for a possible further boost – if necessary even with renewed vaccines, the virologist explains further.

Current refresher recommendations from the Standing Committee on Vaccination

The Standing Vaccination Committee (Stiko) currently recommends the following in addition to primary immunization (consisting of two vaccine doses that should be administered three to six weeks apart, depending on the vaccine):

• A booster shot
  for everyone over the age of twelve. This should be done with an mRNA-based vaccine at least six months after the second vaccine dose. For this, the Stiko recommends a bivalent omicron-adapted vaccine. However, Stiko recommends an omicron-adapted Comirnaty vaccine for people under the age of 30 due to the risk of heart muscle inflammation.
• Two booster shots
  for people from the age of five with an increased risk of a severe course, people from the age of 60 and residents of nursing homes and medical staff
  .
  This should be done with an mRNA-based vaccine at least six months after the second vaccine dose or the first booster dose. For this, the Stiko recommends a bivalent omicron-adapted vaccine. Again, people under the age of 30 should be vaccinated with an omicron-adapted Comirnaty vaccine because of the risk of heart muscle inflammation.

Since a large part of the population in Germany has now had one or more infections, especially since the appearance of Omikron, Stiko also advises that there should be a time interval of at least six months between infection and booster vaccination. It only recommends booster vaccinations every three months for people with a weakened immune system.

According to Stiko, people who have had multiple infections should also get vaccinated. Because a combination of vaccination and infection leads to what is known as hybrid immunity. Only if the immune system repeatedly deals with immunological events such as vaccination or infection does solid protection against a serious illness with Covid-19 as well as hospitalization and death occur.

Fifth vaccination for certain groups of people may make sense

The Stiko does not generally recommend a fifth booster vaccination. However, she points out that, in consultation with the doctor treating you, it can be particularly useful for people at risk, such as the very old and people with a weakened immune system.

Arcturus possibly bypasses immune system

XBB.1.16 is an omicron subvariant that arose from a recombination of BA.2.10.1 and BA.2.75. Compared to XBB, it has three additional mutations in the spike protein. One of these (F486P) is associated with a reduced antibody response, higher transmissibility and a higher disease burden.

Friedemann Weber, Head of the Institute of Virology at the University of Giessen, also confirms that these mutations could be potentially dangerous: “XBB.1.16 has a number of other changes in the genome that not only affect the spike protein, but also the so-called ORF9b -Gen, which is involved in the suppression of the interferon response,” explained when asked by FOCUS Online.

Interferons are messenger substances that are produced by infected cells to warn other cells of the infection and to initiate countermeasures. However, Sars-CoV-2 has a whole range of these so-called interferon antagonists, and ORF9b has not yet been one of the strongest representatives.

Nevertheless, the variant could thereby undermine the immune system of vaccinated and recovered, which explains the sharp increase in infections in India. However, there is still no official evidence that an Arcturus infection would be associated with a higher disease burden, a higher number of hospital and intensive care unit admissions or even an increasing number of deaths.

Infection numbers in Germany are officially declining, but the number of unreported cases is higher

The official infection numbers in Germany are declining – the nationwide incidence is currently only around 24 cases per 100,000 inhabitants – but since not all cases are reported anymore, the RKI also assumes a significantly higher infection burden in the population. Although Germany now has a high level of immunity among the population, it is completely unclear whether this is sufficient to slow down the new variant. Because neither immunity from a Sars-CoV-2 infection, vaccination, or a combination of both lasts forever.

Timo Ulrichs, epidemiologist from Berlin, sees it this way: “The decisive question is whether their antigen structure looks so different that the immunity learned through vaccination and previous infection no longer helps to inhibit the spread and even more so the severe clinical courses of Keeping Covid-19 small,” he explains at the request of FOCUS Online in relation to Arcturus. Therefore, as a precautionary measure, he recommends that risk groups be vaccinated with the new omicron-specific vaccines. “That would be recommended as a prophylactic for all risk groups, if they haven’t already done so,” he emphasizes.

Current vaccination status in Germany

The number of vaccinations in Germany has decreased significantly in the past year. Loud ”
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In Germany, 76.4 percent of the population, i.e. 63.6 million people, are currently basic immunized:

• 62.6 percent of the population, 52.1 million people, also received a booster shot.
• 15.2 percent of the population, 12.6 million people, have received two booster shots.

Currently, 22.1 percent of the population, 18.4 million people, are not vaccinated.