According to the government agency’s preliminary findings on the new variant, the risk of hospital admission for an identified case with Omicron is reduced compared with a case of the Delta variant.
Someone with Omicron is estimated to be as much as 45 percent less likely to attend the emergency department compared with Delta, and as much as 70 percent less likely to be admitted to hospital.
However, Omicron is believed to be infecting more people who have previously had COVID-19, with 9.5 percent of people being reinfected with Omicron.
Omicron also appears to evade vaccines better than previous variants. Though a booster jab is said to provide more protection against the variant, data suggests protection starts to wane 10 weeks after booster vaccination.
The UKHSA findings are consistent with two studies published on Wednesday, both of which suggest the severity of the Omicron variant is relatively mild.
Researchers from the Imperial College London estimated that Omicron patients were 20 to 25 percent less likely to need hospital care and 40 to 45 percent less likely to be hospitalized for one night or more when compared to patients with the Delta variant.
The researchers also estimated that natural immunity, or protection from a prior infection, reduces the risk of hospitalization by 50 percent and the risk of a hospital stay of one night or more by 61 percent.
Scientists in a separate Scotland-wide study called Early Pandemic Evaluation and Enhanced Surveillance of COVID-19 said Omicron is associated with a two-thirds reduction in the risk of hospital admission compared with Delta.
Earlier on Thursday, Tim Spector, professor of genetic epidemiology at King’s College London and the lead scientist on the ZOE COVID Study app, also said that preliminary data based on around 2,500 probable cases reported on the ZOE app suggests that Omicron is milder than Delta.
UK Health Secretary Sajid Javid welcomed the latest data as “promising.”
But he warned that Omicron cases “continue to rise at an extraordinary rate” and “hospital admissions are increasing.”
Javid said the findings are still “early-stage analysis” and it is still “too early to determine next steps.”
He said the government will “continue to monitor the data hour by hour,” and urged the public to “stay cautious this Christmas.”
Zachary Stieber and PA contributed to this report.