The latest findings coincide with findings from South Africa, Great Britain and Denmark: In the course of the analysis of data from almost 70,000 California Covid patients, it has now been shown that Omikron causes less severe courses than other coronavirus variants
Compared to Delta, Omicron infections were in the investigation, which was published online on Tuesday and has not yet been reviewed by external colleagues, only half as likely to be associated with hospitalization.
The scientists analyzed 69,279 symptomatic patients who tested positive for the coronavirus between November 30, 2021 and January 1, 2022. Three quarters of the positive samples contained the omicron variant, the remainder Delta.
Infection under observation
The researchers then followed the people who tested positive to see if they ended up in the hospital. They excluded so-called random Covid patients who presented to hospitals because of other complaints and only tested positive for the coronavirus on arrival from the analysis.
Specifically, it was shown that Omikron reduced the risk of hospitalization by half compared to Delta. In addition, those who came to the hospital with Omikron stayed in the hospital for a shorter period of time. The variant shortened hospital stays by more than three days, a reduction of 70 percent compared to Delta. Fourteen of the Delta infected patients died, while only one Omicron patient died. That equates to a 91 percent reduction in the risk of death.
“It really is a viral factor that is responsible for the lower severity,” said Joseph Lewnard, co-author of the study and an epidemiologist at the University of California, Berkeley.
Root cause research
According to the researchers, one reason for the milder course could be related to the fact that people infected with Omikron now have a stronger immune defense than in previous corona waves. Animal studies also suggest that while Omikron easily infects cells in the upper respiratory tract, it works poorly in the lungs, which could also explain the milder effects.
The vaccinations would also offer protection. “Vaccines are very helpful,” said Lewnard. He and his colleagues found that vaccinated Californians were 64 to 73 percent less likely to be hospitalized than those who were not vaccinated. However, even in unvaccinated individuals, Omikron was less likely to be hospitalized than Delta.
Omicron spreads “like wildfire”
However: Despite the apparently lower pathogenicity of Omikron, hospitals in the USA are struggling with a strong influx of coronavirus cases. According to Lewnard, this is due to the fact that the variant is spreading like wildfire. On average they get loud New York Times in the United States, more than 730,000 people test positive each day, nearly three times as many as last winter.
“Because it is a communicable disease, there will inevitably be a large number of hospitalizations at some point,” Lewnard said in the New York Times quoted.