The New York Times, January 11, 2022
A new study of nearly 70,000 Covid patients in California demonstrates that Omicron causes less severe disease than other coronavirus variants, results that align with similar findings from South Africa, Britain and Denmark, as well as a host of experiments on animals.
Compared with Delta, Omicron infections were half as likely to send people to the hospital. Out of more than 52,000 Omicron patients identified from electronic medical records of Kaiser Permanente of Southern California, a large health system, the researchers found that not a single patient went on a ventilator during that time.
“It’s truly a viral factor that accounts for reduced severity,” said Dr. Lewnard, an epidemiologist at the University of California, Berkeley who was an author of the study, which was posted online on Tuesday and has not yet been published in a scientific journal.