Researchers for a new study say Omicron appears to be milder than the Delta variant of COVID-19, leading to up to 80% fewer hospitalizations.
Of the people who contract the virus and are hospitalized, they’re also 70% less likely to be admitted to the intensive care unit or be put on a ventilator compared to those with Delta, The Daily Mail reported on the study led by South Africa’s National Institute for Communicable Diseases (NICD).
“So even though cases of omicron were less likely to end up in hospital than cases of delta, it is not possible to say whether this is due to inherent differences in virulence or whether this is due to higher population immunity in November compared to earlier in the year,” Paul Hunter, a professor of medicine at the U.K.’s University of East Anglia, told the Daily Mail.
Another study found much of the same. “A separate study out of Scotland, by scientists at the University of Edinburgh and other experts, suggested the risk of hospitalization was two-thirds less with omicron than delta. But that study pointed out that the nearly 24,000 omicron cases in Scotland were predominantly among younger adults ages 20-39. Younger people are much less likely to develop severe cases of COVID-19,” said the Associated Press.
“This national investigation is one of the first to show that Omicron is less likely to result in COVID-19 hospitalization than Delta,” researchers wrote, the AP said. While the findings are drawn from early data, “they are encouraging,” the authors wrote.
Neither of the studies has yet been reviewed by peers.
Meanwhile, according to a report from the British government, which will release the early data in the coming days, the Omicron variant of SARS-CoV-2 is milder than the Delta variant.
The UK Health Security Agency (UKHSA), which operates much like the U.S. Centers for Disease Control and Prevention (CDC), found that those who contract Omicron are less likely to become severely ill compared to people who get the Delta variant, according to the data, reports Politico.
“More people are likely to have a mild illness with less serious symptoms — probably in part due to Britain’s large number of vaccinated and previously infected people, and possibly because Omicron may be intrinsically milder,” Politico reported. “Chief Medical Officer Chris Whitty has previously cautioned against too much optimism based on the initial optimistic signs from South Africa in the past few weeks. However, the UKHSA’s view after studying cases in Britain is that Omicron is indeed usually less severe than Delta.”
But the report included one caveat. “The less good news is that while Omicron seems milder overall, the UKHSA has found it is not necessarily mild enough to avoid large numbers of hospitalizations. The experts have found evidence that for those who do become severely ill, there is still a high chance of hospitalization and death.”
“The UKHSA has also confirmed that transmissibility of Omicron is very high, meaning that even though it is milder, infections could rocket to the point large numbers still end up in hospital — essentially negating the reduction in severity. NHS staff shortages due to widespread infections also have to be taken into account. Boris Johnson said on Tuesday that there was still ‘uncertainty’ on exactly how severe Omicron is, and how this impacts the hospitalization rate,” said the report.
Another UK study of early data about the Omicron variant has found that the most common symptoms are akin to the common cold.
The ZOE COVID Symptoms Study, which has been tracking symptoms reported by participants using a smartphone app, reported that the top five symptoms for Omicron are runny nose, headache, fatigue (mild or severe), sneezing, and sore throat. The data were collected between December 3 and 10 in London.