The forecasts of the experts on the corona mutation Omikron are full of concern: “The Omikron wave continues to pile up and with a dynamic that we have not seen in the pandemic,” said Lothar Wieler, President of the Robert Koch Institute Institute on Friday in a press conference. Experts from the World Health Organization (WHO) have calculated that in two months more than half of the people in Europe could have been infected with omicron.
It is true that omicron leads to milder disease progression than an infection with the delta variant. Nevertheless, the number of people affected can put a heavy strain on the health system. Due to the mass of infections, one has to be prepared for the number of hospital admissions and deaths to increase again, explained Wieler. But the wave will probably not block the intensive care units this time. Instead, the beds on the normal wards could become scarce.
The fact that an omicron infection causes only mild symptoms may be true for many people. The risk of hospitalization is at least a third and at most two-thirds that of Delta – so definitely lower. But a closer look shows that the virus remains a serious threat, especially for the older part of the population who do not yet have adequate vaccination protection. Of the 80 people who died from the new variant in Germany in the first weeks of January, two thirds were older than 80 years.
Many younger people with omicron in the hospital
In Germany, three million people over the age of 60 have not yet been vaccinated, and almost nine million have not been boosted. All of them are only insufficiently protected against the rapidly spreading variant. Data from Denmark showed that the protective effect against an omicron infection after two vaccinations is only between 25 and 30 percent, while it increases to around 80 percent in people who have been boosted, explains Andreas Schuppert, head of the Institute for Computational Biomedicine at RWTH Aachen University. The number of registrations from the Robert Koch Institute also shows another abnormality. In the hospitals there are many younger people with an omicron infection. The absolute number of patients between 15 and 34 years is larger than those between 60 and 80 years.
We have been confronted with the corona virus and the pandemic for almost two years now. The large complex of topics provides a lot of material for reporting. Here is a selection of articles about new variants, symptoms such as Long Covid and news about the vaccines.
That is why Clemens Wendtner warns against misunderstood security. “Mild doesn’t mean harmless,” explains the head of the special unit for highly contagious infections at Munich Clinic Schwabing. The doctor reports from his everyday life about a problem that primarily affects high-risk patients. The drug Ronapreve, which has been used successfully to date, remains ineffective against Omikron because the antibodies Casirivimab and Imdevimab it contains do not recognize the new virus mutation. “Here we no longer have a chance to intervene therapeutically in patients with a mild course in the early phase,” says Wendtner.
An infection with the omicron variant triggers slightly different symptoms than those previously known from Corona. According to the British ZOE-COVID statistics, a runny nose, headache and sore throat, sneezing and increased fatigue are particularly common. In this study, omicron-infected volunteers report their symptoms via a mobile phone app. Accordingly, fever and the loss of smell and taste, which is otherwise common with corona infections, appear to occur less frequently than with the previous variants.
Omicron reaches the deeper parts of the lungs less often
The milder course can be explained most easily with the observation that the disease no longer reaches the deeper lung sections quite as often and thus rarely triggers severe courses. Because if the lungs are infected by the virus, many more cells die as a result of the inflammatory immune reaction that is triggered. The poor oxygen supply weakens the whole body. Animal experiments with hamsters and mice and experiments with lung organoids confirm that the virus concentration in the lungs of the infected animals with Omicron is at least ten times lower than with an infection with the other variants. Scientists already have a theory as to why the mutations behave so differently. Omicron doesn’t bind to a protein called TMPRSS2, so it can’t use a mechanism to penetrate cells in the lungs that has made Delta so dangerous. This mechanism plays a lesser role when it spreads in the nasopharynx, and Omikron has advantages for us here in many cases.
However, the scientists also provide evidence that even a mild course of the disease can lead to longer-lasting damage to several organs. As part of the regular Hamburg City Health Study (HCHS), researchers at the Hamburg-Eppendorf University Hospital have extensively examined 443 people with only mild symptoms after a SARS-CoV-2 infection and compared the data with participants who did not have COVID-19. They found an average decrease in cardiac output of one to two percent and, in the blood analysis, clear indications of a higher load on the heart. The lung and kidney function of the patients was two to three percent below the values of the comparison group, thrombosis in the leg veins occurred more frequently. “The realization that even a mild course of the disease can lead to damage to various organs in the medium term is of the utmost importance, especially with regard to the omicron variant, which mostly seems to be associated with milder symptoms,” says Raphael Twerenbold, cardiologist and scientific head of the study center.
The Hamburg data support the finding that a SARS-Cov-2 infection can also have chronic consequences that persist three months after infection and limit the quality of life of those affected. These long-Covid effects remain the great uncertainty of the corona pandemic. How great the long-Covid danger is for Omicron-infected people will only be answered in the spring, when the virus has been on the road for a few months. Well-known European scientists have therefore appealed in an open letter to those responsible in politics to continue all possible protective measures to contain the pandemic and not to speculate on a mild course.
(jle)