A new US study of nearly 70,000 COVID-19 positive people has shown a substantially lower risk of hospitalization and death from the Omicron variant even after controlling for growing population immunity levels, according to Medical Xpress.

The study, which has not yet been peer-reviewed, found that people infected with Omicron were 50% less likely to be hospitalized, 75% less likely to need intensive care, and 90% less likely to die compared to those infected with Delta.

Nearly 52,000 people were infected with Omicron, but none required mechanical ventilation. Of 17,000 patients infected with Delta, 11 ended up on a ventilator.

For Omicron, hospital stays lasted for about 1.5 days, whereas for Delta, hospitalizations lasted for five days. Around 90% of Omicron patients were discharged within two to three days.

Researchers from the University of California, Berkeley, Kaiser Permanente, and the Centers for Disease Control and Prevention (CDC) conducted the study.

The study findings build on accumulating population-level research from countries including South Africa and Britain, but also on animal and human tissue-based testing, which have found Omicron replicates better in the upper airways compared to the lungs, according to Medical Xpress.

CDC Director Dr. Rochelle Walensky said Wednesday, “This study controlled for important key parameters such as age, sex, prior SARS-CoV-2 infection, prior vaccination, and comorbidities.”

The researchers said the findings suggest that Omicron is “intrinsically less severe than Delta,” and observed reductions in severe cases are not only the result of more people being vaccinated and infected over time.

The study also noted reduced vaccine efficacy against Omicron, but there was substantial ongoing protection against severe outcomes.

Dr. Walensky cautioned that the study findings should not lead to complacency, as Omicron’s extreme transmissibility is still sweeping the nation, exhausting the health care system and health workers.

The United States is reporting an average of 750,000 cases a day, with over 150,000 COVID hospitalizations and more than 1,600 daily deaths.

Dr. Anthony Fauci, the nation’s top infectious disease expert, said Tuesday, “Omicron, with its extraordinary, unprecedented degree of efficiency of transmissibility, will ultimately find just about everybody.”

However, “after the country emerged from its current wave, it would transition towards a future of living with the virus, with COVID vaccines moderating severe disease for the majority and effective treatments available for the most vulnerable,” added Dr. Fauci, one of the lead members of the White House COVID-19 Response Team. The article was published in Medical Xpress.