New York,  Patients hospitalised with the Omicron or Delta variants of Covid-19 required similar levels of respiratory support and intensive care, according to a new study.

Even though Omicron has generally been touted as mild, the findings led by Johns Hopkins University researchers indicate that infections with the highly contagious variant should not be underestimated.

"It is a common belief that the Omicron variant is less severe than previous variants," said lead author Heba Mostafa, Assistant Professor of pathology at the University's School of Medicine.

"For many people, Omicron is not a mild infection at all," Mostafa added.

For the study, the team collected clinical specimens from over 2,000 patients who tested positive for SARS-CoV-2, then determined which variant each patient had been infected with. Next, they measured viral load, the amount of the virus found in each patient's body.

The results, published in the eBioMedicine journal, showed that patients with Omicron were less likely than patients with Delta to require hospitalisation, regardless of vaccination status.

Only 3 per cent of patients with Omicron were admitted to the hospital, compared with 13.8 per cent of patients with Delta.

However, patients with Omicron who required hospitalisation showed a similar need for supplemental oxygen and intensive care as hospitalised patients with Delta. For patients with Omicron admitted to the hospital, 67.6 per cent required supplemental oxygen and 17.6 per cent were taken to the intensive care unit (ICU).

Similarly, 73 per cent of patients hospitalised with delta needed supplemental oxygen, and 25.4 per cent required ICU-level care.

The study found no significant differences in viral loads between patients with Omicron and those with Delta, regardless of vaccination status.

Mostafa said the research shows it is imperative for people to take Omicron and potential future variants seriously.