H5N1 highly pathogenic avian influenza virus (HPAIV) infection has been reported in poultry and humans with expanding clade designations. Therefore, a vaccine that induces immunity against a broad spectrum of H5N1 viruses is preferable for pandemic preparedness. We established a second H5N1 vaccine candidate, A/duck/Hokkaido/Vac-3/2007 (Vac-3), in our virus library and examined the efficacy of inactivated whole particles of this strain against two clades of H5N1 HPAIV strains that caused severe morbidity in cynomolgus macaques. Virus propagation in vaccinated macaques infected with either of the H5N1 HPAIV strains was prevented compared with that in unvaccinated macaques. This vaccine also prevented propagation of a pandemic (H1N1) 2009 virus in macaques. In the vaccinated macaques, neutralization activity, which was mainly shown by anti-hemagglutinin antibody, against H5N1 HPAIVs in plasma was detected, but that against H1N1 virus was not detected. However, neuraminidase inhibition activity in plasma and T-lymphocyte responses in lymph nodes against H1N1 virus were detected. Therefore, cross-clade and heterosubtypic protective immunity in macaques consisted of humoral and cellular immunity induced by vaccination with Vac-3.

The life cycle of EBV is regulated by epigenetic modifications, such as CpG methylation and histone modifications. Here, we found that the expression of EZH2, which encodes a histone H3K27 methyltransferase, was induced by EBV infection; therefore, we generated EZH2-KO cells to investigate the role of EZH2 in EBV-infected Akata B cells. Disruption of EZH2 resulted in increased expression of EBV genes during the lytic phase and, therefore, efficient viral replication and progeny production. Our results shed light on the mechanisms underlying reactivation from an epigenetic point of view and further suggest a role for EZH2 as a form of innate immunity that restricts viral replication in infected cells.

25Highly pathogenic avian influenza viruses (HPAIVs) have spread in both poultry and wild 26

Background Clinical characteristics, including laboratory parameters, of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant have been limited. Methods This retrospective case-control study was conducted in a single hospital. Patients with coronavirus disease 2019 (COVID-19) who visited the Asahikawa City Hospital outpatient department as new patients and underwent blood tests were included in this study. We analyzed the data from January 2022 to April 2022 during the Omicron phase and from April 2021 to October 2021 during the Delta phase. Patients who were treated at other hospitals after visiting our hospital were excluded. All blood tests were performed before treatment for COVID-19 was initiated. Demographic information, laboratory data, and clinical courses were extracted from electronic medical records. We matched the two groups by age and comorbidities and compared their characteristics. We also analyzed factors associated with pneumonia in the Omicron phase. Results A total of 151 Omicron patients and 167 delta patients were analyzed in this study. The mean age, rate of comorbidities, and vaccination were significantly higher in the Omicron group. The number of patients with pneumonia or those requiring oxygen, admissions, or both was significantly lower in the Omicron group. Lactate dehydrogenase (LDH), C-reactive protein (CRP), ferritin, aspartate aminotransferase (AST), and neutrophil-to-lymphocyte ratio (NLR) levels were significantly lower in the Omicron group. Compared with the mild symptom and pneumonia groups in the Omicron group, older age, higher body mass index (BMI), higher non-vaccination, higher LDH, and higher CRP levels were associated with the pneumonia group. Conclusion The Omicron variant is associated with a reduction in hospitalization and the risk of pneumonia compared to the delta variant in a real-life clinical setting. In the Omicron variant, the risk of pneumonia is related to high-risk factors, laboratory data such as LDH and CRP levels, and no vaccination.

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