This electron microscope photo shows the coronavirus's omicron variant successfully isolated at the National Institute of Infectious Diseases. (Photo courtesy of the National Institute of Infectious Diseases).

       TOKYO -- While the coronavirus's omicron variant has been reported to be more transmissible than the delta variant, South Africa and the United Kingdom have reported the possibility that patients infected with the former are less likely to be hospitalized.

       Infections with the omicron variant have been confirmed in over 100 countries and regions, and information on severe cases have gradually been gathered. A team at Imperial College London conducted a study comparing around 56,000 subjects infected with the omicron variant and 269,000 individuals infected with the delta variant. The risk of needing to be treated at the hospital for patients with the omicron variant was 15% to 25% lower than for patients with the delta variant, while risks of being hospitalized for one night or more due to omicron was between 40% and 45% lower than with its counterpart.

       Furthermore, a team at the University of Edinburgh analyzed the data of about 5.4 million individuals in Scotland, and found that there is a two-thirds reduction in hospitalization risks due to omicron infections compared to delta.

       A South African study reported similar results, with hospitalization risks for omicron being 70% to 80% lower than that for the delta variant and other coronavirus strains. However, a majority of the omicron patients examined by the University of Edinburgh team belonged in the 20 to 39 age group, and the team pointed out the necessity to bear in mind that the study examined an age group that has smaller risks of developing severe cases compared to elderly patients.

       Meanwhile, the World Health Organization and other bodies have reported that the omicron variant is more transmissible and has higher risks of reinfection than the delta variant. It is also suspected that omicron lowers vaccines' efficacy to prevent infections.

       Anthony Fauci, chief medical adviser to U.S. President Joe Biden, spoke about the omicron variant during a Dec. 22 press conference, saying that there is a decrease in severity compared to delta. However, he also sounded the alarm and said, "There is no doubt that we are dealing with a highly transmissible virus."

       Since an infection with the omicron variant was first announced in South Africa on Nov. 24, cases spread to 106 countries and regions as of Dec. 21. Considering it took around nine months for the delta variant to reach over 100 countries, omicron's high transmissibility stands out. At a Dec. 22 press conference, Takaji Wakita, head of the National Institute of Infectious Diseases, commented, "It is known that once omicron infections become more widespread, a rapid outbreak follows. As it is also possible that the health care system will quickly come under strain, we must prepare."

       (Japanese original by Naomi Hayashi, Lifestyle and Medical News Department)

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