- 著者
- Kosuke SODA Hirohisa MEKATA Tatsufumi USUI Hiroshi ITO Yuto MATSUI Kentaro YAMADA Tsuyoshi YAMAGUCHI Toshihiro ITO
- 出版者
- JAPANESE SOCIETY OF VETERINARY SCIENCE
- 雑誌
- Journal of Veterinary Medical Science (ISSN:09167250)
- 巻号頁・発行日
- pp.23-0121, (Released:2023-09-26)
In the winter of 2021–2022, multiple subtypes (H5N8 and H5N1) of high pathogenicity avian influenza viruses (HPAIVs) were confirmed to be circulating simultaneously in Japan. Here, we phylogenetically and antigenically analyzed HPAIVs that were isolated from infected wild birds, an epidemiological investigation of affected poultry farms, and our own active surveillance study. H5 subtype hemagglutinin (HA) genes of 32 representative HPAIV isolates were classified into clade 2.3.4.4b lineage and subsequently divided into three groups (G2a, G2b, and G2d). All H5N8 HPAIVs were isolated in early winter and had HA genes belonging to the G2a group. H5N1 HPAIVs belong to the G2b and G2d groups. Although G2b viruses were widespread throughout the season, G2d viruses endemically circulated in Northeast Japan after January 2022. Deep sequence analysis showed that the four HPAIVs isolated at the beginning of winter had both N8 and N1 subtypes of neuraminidase genes. Environmental water-derived G2a HPAIV, A/water/Tottori/NK1201-2/2021 (H5N8), has unique polymerase basic protein 1 and nucleoprotein genes, similar to those of low pathogenicity avian influenza viruses (LPAIVs). These results indicate that multiple H5 HPAIVs and LPAIVs disseminated to Japan via transboundary winter migration of wild birds, and HPAIVs with novel gene constellations could emerge in these populations. Cross-neutralization test revealed that G2a H5N8 HPAIVs were antigenically distinct from a G2b H5N1 HPAIV, suggesting that antibody pressure in wild birds was involved in the transition of the HPAIV groups during the season.
- 著者
- Ippei Watanabe Kentaro Yamada Akira Aso Okio Suda Takashi Matsumoto Takaaki Yahiro Kamruddin Ahmed Akira Nishizono
- 出版者
- 国立感染症研究所 Japanese Journal of Infectious Diseases 編集委員会
- 雑誌
- Japanese Journal of Infectious Diseases (ISSN:13446304)
- 巻号頁・発行日
- vol.66, no.1, pp.17-21, 2013 (Released:2013-01-22)
- 参考文献数
- 23
- 被引用文献数
- 4 12
A mass rabies vaccination of dogs has been conducted annually in Japan over the last 60 years. To assess both current levels of rabies virus-neutralizing antibody (VNA) in dogs and the rationale for current vaccination procedures, we used a rapid fluorescent focus inhibition test to determine VNA levels in 756 dogs that had visited animal hospitals in Japan. We found that 51.1% of the dogs that had received 1 rabies vaccination had protective VNA levels (≥0.5 IU/ml) with a geometric mean of 0.61 IU/ml. In contrast, 97.8% of the dogs that had been vaccinated at least twice had protective VNA levels with a geometric mean of 7.86 IU/ml. Furthermore, 97.9–100% of the dogs vaccinated at least twice retained protective VNA levels into the second year after the last vaccination. Although VNA levels in the dogs vaccinated at least twice tended to decline 2 years after the last vaccination, 78.9% retained protective VNA levels. Thus, the current rabies vaccination schedule provides adequate protection, but the registration system and vaccination schedule needs to be improved to ensure that increased numbers of dogs are vaccinated against rabies.