Omikron XBB.1.5 – the super variant
The Omikron XBB.1.5 subline is currently spreading rapidly in the USA and could soon dominate the infection scene in Europe as well. The variant is also referred to as the “octopus”. It appears to be the most infectious variant of Sars-CoV-2 to date.
Genetic mix of two omicron variants
Higher infectiousness
XBB.1.5 appears to be able to dock onto the body’s cells even more easily and thus be more infectious than any of its predecessors. Experts believe it is the most infectious variant of Sars-CoV-2 to date.
Vaccinations continue to protect
But there is no evidence that vaccinations do not continue to protect against severe disease. For example, although hospitalizations in the United States have increased because of the many XBB.1.5 cases, they have not increased disproportionately.
No evidence of higher risk
However, since this variant of the virus appears to be even more contagious overall, it could make the current wave a bit more severe, with all the consequences for hospital loads and long covid consequences.
What is Omikron?
Omicron (B.1.1.529) is a mutation-derived variant of the Sars-CoV-2 coronavirus, and several subgroups of Omicron have since emerged. Currently, the different Omikron variants dominate the spread of Sars-CoV-2 worldwide.
Fitness advantage: Why Omikron is more contagious.
The different Omikron variants are actually objectively more contagious than previous Sars-CoV-2 variants. For example, they can penetrate body cells more effectively and replicate more. This fitness advantage causes Omikron-infected individuals to infect significantly more people around them, on average, than people with the original virus under the same conditions.
Immune escape: Why you get infected despite vaccination
Due to the changes in the spike protein, Omikron partially undermines the protection provided by vaccinations. This is also true for immunity after previous infections. Such immune escape is a natural part of the adaptation of viruses to increasing immune protection in the population.
Mild courses on average
The most common Omikron symptoms
Overall, Omikron appears to cause similar symptoms to its predecessors. However, depending on the study, Omikron symptoms vary in frequency.
Five signs are considered the main symptoms of omicron
- Cough
- Rhinitis
- Sore throat
- Headache
- Fatigue
Other accompanying symptoms include fever and loss of appetite. Skin rashes, nausea and diarrhea occur less frequently.
Less respiratory distress, fewer pneumonias
Compared to earlier SARS-CoV-2 variants, omicron replicates primarily in the upper airways. The lung tissue itself is less affected. This provides an explanation for why respiratory distress and pneumonia are less common in omicron.
What is the course of omicron?
Omicron infection appears to be more likely to be mild to mild than infections with earlier variants. Pneumonia occurs less frequently.
Apart from slightly different frequencies of the various symptoms, the disease course remained the same in Omikron.
You can read more details about the course of the disease in the main text on Covid-19.
How long is the incubation period for Omikron?
The incubation period, the time from infection to onset of symptoms, averages four to six days for SARS-CoV-2. With Omikron, however, the incubation period is somewhat shorter.
How long is one contagious with Omikron?
An infected person can pass on Omikron as early as three days after infection – even before they notice any symptoms themselves. For comparison: Delta-infected persons had four days. Shortly before the onset of symptoms, the viral load with Omikron – and thus the infection rate – is even particularly high. The high infectivity then continues for several days.
How long positive for omicron?
In more severely ill patients, however, the infection period can be much longer, as the immune system has a hard time defeating the virus.
What are the omicron variants?
Sars-CoV-2 has evolved steadily through mutation since its discovery in the fall of 2019. Major genetic changes are classified by experts as new variants and are now named after the Greek alphabet. The most recent variant to date is called Omicron.
These variants in turn split into sublines. Two Omikron sublines are currently attracting particular attention:
- Omikron BQ.1.1 bears the epithet Cerberus, after the hellhound of Greek mythology. BQ.1.1 is a subline of Omikron BA5.
- Omikron XBB.1.5, also called Kraken, evolved from the recombination of two viruses from the Omikron BA.2 lineage.
How contagious is Omikron?
Within house communities, for example, Omicron is three times more likely than Delta to be transmitted to the family.
Long covid after omicron
Omicron infections are somewhat milder on average than those caused by earlier variants. However, patients are not immune to long covid. Even mild courses can result in long-lasting symptoms such as severe fatigue or concentration problems as late effects of Omikron.
How safe are rapid tests at Omikron?
Rapid tests detect so-called antigens. These are certain proteins that the virus brings with it. Since the virus has meanwhile evolved away from the original pathogen, the question arises with each new variant whether the tests work less well.
However, rapid tests per se are less reliable overall than PCR tests. They are only effective at a certain virus concentration. False negative and also false positive results are therefore frequent. They therefore do not provide certainty as to whether one has been infected or not – regardless of the corona variant.
How well does vaccination against Omikron work?
When considering the effectiveness of vaccination protection, two important aspects are distinguished: first, protection against infection per se, and second, protection against severe disease progression in the event of infection.
Lower protection against infection
Good protection against severe courses
The good news, however, is that corona vaccinations are nevertheless very effective in protecting against severe courses of the disease. This is because it is not so much the antibodies that are important here, but rather the cellular immune response. The T cells involved continue to recognize the omicron variant well and in a targeted manner.
Currently, there is no evidence that vaccination is less protective against newer omicron variants.
