Naoyuki Miyashita: First Department of Internal Medicine, Division of Respiratory Medicine, Infectious Disease and Allergology, Kansai Medical University, 2-3-1 Shin-machi, Hirakata, Osaka, 573-1191, Japan. Electronic address: miyashin@hirakata.kmu.ac.jp.
Yasushi Nakamori: Department of Emergency Medicine, Kansai Medical University Medical Center, 10-15 Bunen-cho, Moriguchi, Osaka, 570-8507, Japan.
Makoto Ogata: First Department of Internal Medicine, Division of Respiratory Medicine, Infectious Disease and Allergology, Kansai Medical University, 2-3-1 Shin-machi, Hirakata, Osaka, 573-1191, Japan.
Naoki Fukuda: First Department of Internal Medicine, Division of Respiratory Medicine, Infectious Disease and Allergology, Kansai Medical University, 2-3-1 Shin-machi, Hirakata, Osaka, 573-1191, Japan.
Akihisa Yamura: First Department of Internal Medicine, Division of Respiratory Medicine, Infectious Disease and Allergology, Kansai Medical University, 2-3-1 Shin-machi, Hirakata, Osaka, 573-1191, Japan.
Tomoki Ito: First Department of Internal Medicine, Division of Respiratory Medicine, Infectious Disease and Allergology, Kansai Medical University, 2-3-1 Shin-machi, Hirakata, Osaka, 573-1191, Japan.
OBJECTIVES: We investigated the incidence and risk factors for requiring intensive care unit (ICU) admission or invasive mechanical ventilation (IMV) in pneumoniapatients with Omicron subvariants between the 9th and 11th waves. METHODS: We analyzed 536 patients with pneumonia caused by SARS-CoV-2 Omicron subvariants (175 cases were XBB lineage, 169 cases were JN.1, and 192 cases were KP.3 subvariants). RESULTS: Rates of ICU admission or requirement for IMV were significantly higher in patients with the KP.3 subvariant group than those with the XBB lineage and JN.1 subvariant groups. Patient age (odds ratio [OR]: 1.09, P < 0.001), immunodeficiency (OR: 2.82), 2 or more co-morbid illnesses (OR: 2.54), and more than 2 years since last vaccination (OR: 1.29) were significantly associated with increased severity. CONCLUSIONS: Physicians should recommend SARS-CoV-2 vaccination and positive use anti-SARS-CoV-2 drugs when COVID-19 is found in patients who are ���65 years old or who have multiple comorbidities.
