The decreased severity of the Omicron COVID-19 variant may be a "harbinger" of an end to the global pandemic caused by virus. Initial data from South Africa indicates that the variant results in a quarter of deaths associated with earlier variants.

In the first study conducted to assess the risk of fatalities presented by Omicron researchers assessed the progress of COVID patients admitted to the Steve Biko Academic Hospital and the Tshwane District Hospital, the latter of which has been converted into a COVID specialist facility.

The hospitals are located in the City of Tshwane, the region of South Africa that was the first global epicenter of Omicron.

"There are clear signs that case and admission rates in South Africa may decline further over the next few weeks," the authors wrote.

"If this pattern continues and is repeated globally, we are likely to see a complete decoupling of case and death rates suggesting that Omicron may be a harbinger of the end of the epidemic phase of the COVID pandemic ushering in its endemic phase."

The Centers for Disease Control and Prevention (CDC) describes an endemic as a sudden localized rise in a particular disease that is usually present in a community. This means that the disease's spread is predictable. This is in contrast to a pandemic, which the CDC defines as an: "Event in which a disease spreads across several countries and affects a large number of people."

The researchers continued: "There was decreased severity of disease in the Omicron-driven fourth wave in the City of Tshwane, its first global epicenter, with fewer deaths, ICU admissions, and a shorter length of stay."

They said the younger age profile of patients was probably a factor in this observation.

The authors of the study, published in the International Journal of Infectious Diseases, note that the current Omicron wave increased at a faster rate than previous waves, completely displacing the Delta variant within weeks. But, five weeks following its commencement, they observed a decline in both cases and hospital admissions.

To obtain their results the team compared 466 COVID admissions in the first 33 days of the spread of the Omicron variant, to 3,976 admissions that occurred over the previous 18 months since May 2020.

A lab tech holds a vial containing Omicron COVID Variant. A new study indicates that the Omicron variant may be the "harbinger" of the virus becoming endemic. Diy13/Getty

This resulted in a clinical profile of 98 patients at the peak of the Omicron wave in the region, from December 14 to 15. The researchers found that 4.5 percent of patients admitted to the hospitals during the Omicron wave died. This is compared with 21.3 percent in the period before the start of the Omicron wave.

Hospital admissions dropped from 4.4 percent in previous waves to 1 percent during the Omicron wave, and the length of hospital stays also reduced from an average of 8.8 days to an average of around four days.

Mark Jit, Professor of Vaccine Epidemiology at the London School of Hygiene & Tropical Medicine (LSHTM), who was not involved in the study, told Newsweek there have been a number of reports suggesting Omicron causes less severe disease compared to Delta.

"We need to interpret these results carefully because Omicron is more likely to infect people with prior immunity from previous COVID infections or from vaccination compared to Delta," he said.

"Hence they have a less severe disease because their prior immunity is still giving them some protection from the worst effects of COVID. We also need to compare the people getting infected with both variants in terms of their age and vulnerability. "

Jit added that Omicron is still severe enough to cause many hospital admissions and deaths in a large outbreak. He said: "We have to remember that Delta itself is more severe than the original strain of COVID we saw in March 2020. Nevertheless, it does suggest that the size of the 'Omicron wave' in the U.K. and around the world will be smaller than some of the worst-case projections."

Martin McKee, a professor of European public health at LSHTM who was not involved in the research, also urged caution. He told Newsweek: "The commonly expressed view that viruses mutate to become less dangerous has not stood the test of time as we have gone through progressively more concerning variants.

"While welcoming the evidence that Omicron appears to be less severe in a population with a high level of immunity, we cannot make any assumptions about what comes next."

McKee said history has shown when handling and controlling epidemic disease, concerted human action is key, whether it was ensuring clean water to prevent cholera, vaccination to prevent smallpox, or improved living conditions and, eventually, chemotherapy to tackle tuberculosis. "Those who advocate 'living with the virus' are relying on a sense of hope that is not justified by history," he said.

Previously Jit explained to Newsweek that becoming endemic would likely not mean COVID should be treated less seriously. Drawing a comparison to flu, he said: "Flu was actually one of the leading causes of mortality in the U.K. prior to 2020, and partly responsible for a big spike of hospital and ICU admissions in winter.

"We dealt with it mainly by trying to get people vaccinated every winter, especially healthcare workers and the most vulnerable people. In the long run, we might deal with COVID in a similar way, although mortality from COVID is unfortunately likely to exceed historical flu mortality for at least the next couple of years."

Jit said that rather than place too much reliance on COVID evolving into a less deadly virus, we should continue to deal with it in existing ways. He concluded: "Vaccination at high coverage is the only long-term exit strategy to the pandemic we have."