In a new study of nearly 70,000 Covid patients in California, researchers discovered that Omicron causes less severe disease than other coronavirus variants, findings that are consistent with similar findings from South Africa, the United Kingdom and Denmark, as well as results from a slew of animal experiments.
When compared to Delta infections, Omicron infections were half as likely to result in persons being admitted to the hospital. The researchers discovered that, out of more than 52,000 Omicron patients identified from electronic medical records at Kaiser Permanente of Southern California, a huge health system, not a single patient was placed on a ventilator during that time period.
Doctor Lewnard, an epidemiologist at the University of California, Berkeley, and one of the research’s authors, said, “It is really a viral element that accounts for lower severity.” The study was presented online on Tuesday and has not yet been published in a scientific publication.
Despite the less severe virulence of Omicron, hospitals in the United States are struggling to keep up with the inflow of coronavirus patients. Dr. Lewnard said that this was a consequence of the variation spreading like wildfire across the population. Every day in the United States, more than 730,000 individuals test positive for HIV, which is almost three times the previous record of 400,000 during the previous winter.
In recent weeks, reports from the United Kingdom and numerous other nations have shown that Omicron is associated with a decreased risk of hospitalisation. Doctor Lewnard and his colleagues started investigating electronic health data stored by Kaiser Permanente of Southern California, which covers 4.7 million individuals, as soon as the variation was discovered in the United States last month.
In order to determine whether or not the individuals who tested positive ended up in the hospital, researchers tracked down the individuals who tested positive. It was decided to exclude the so-called incidental Covid patients, who were admitted to hospitals for a variety of reasons and then tested positive with the coronavirus after they arrived.
According to the findings of the research, as compared to Delta, Omicron reduced the chance of hospitalisation by half, and those who were admitted to the hospital while taking Omicron were discharged sooner. When compared to Delta, the variation reduced hospital stays by more than three days, a reduction of more than 70 percent.
As evidence has accumulated showing Omicron is less severe than previously thought, experts have tried to determine why. One explanation is that the persons who have been infected with Omicron have stronger immune responses than those who have been infected in prior rounds.
In other places, researchers have discovered that early infections with different types lessen the likelihood that patients may get critically unwell as a result of the Omicron virus infection. Vaccination provides additional protection.
“Vaccines are quite beneficial,” Dr. Lewnard said. He and his colleagues discovered that persons who were vaccinated in California were 64 to 73 percent less likely to be hospitalised than those who were not vaccinated.
Even among those who had not been vaccinated, Omicron was shown to be less likely than Delta to result in hospitalisation.
Dr. Lewnard said that the further investigation revealed that Omicron was essentially less severe than previously thought. The findings of animal studies imply that Omicron infects cells in the upper airway with ease but performs poorly in the lungs, which might explain its lesser effects in humans.
