influenza vaccine (Grippol)

Co-circulation of H5N1 and H5N6 High Pathogenicity Avian Influenza Viruses in Migratory Birds at a Coastal Wintering Site in China.

Hu Xinyu X, Xiang Haiyang H, Wang Wenhao W, Kong Yunyi Y et al.

Since 2020, H5Nx high Pathogenicity avian influenza viruses (HPAIVs) belonging to hemagglutinin (HA) clade 2.3.4.4b have undergone widespread dispersal in wild birds, posing substantial threats to global poultry populations and mammals worldwide. In this study, we report the co-circulation of clade 2.3.4.4b H5N1 and H5N6 HPAIVs associated with mortality events in Anseriformes and Charadriiformes at a coastal wintering site in Fujian Province, China. H5N1 and H5N6 viruses were identified in 4 species of waterfowl (Bean Goose, Eastern Spot-billed Duck, Eurasian Wigeon, and Eurasian Curlew). Phylogenetic analysis indicated that these H5N1 and H5N6 isolates were clade 2.3.4.4b strains circulating within Eurasia and lacked known mammalian adaptation markers in key proteins. The infected birds exhibited severe systemic multi-organ pathology, with the most pronounced damage observed in the lungs. H5N6 and H5N1 viruses caused lethal injury in BALB/c mice, with H5N1 leading to systemic infection. Environmental sampling also revealed the presence of H5N1 HPAIVs alongside low-pathogenicity avian influenza viruses (LPAIVs) such as H3N1 and H6N1. Our findings highlight the complex and dynamic transmission patterns of H5 HPAIV in wild bird populations and the substantial threat they pose to mammals, underscoring the critical importance of sustained surveillance for high pathogenicity avian influenza in wild birds.

A subunit vaccine protects A129 mice from death and joint swelling against lethal Chikungunya virus challenge.

Li Jiangfan J, Fang Ting T, Song Liyuan L, Qiang Li L et al.

Chikungunya virus (CHIKV) is primarily transmitted to humans through bites of infected Aedes mosquitoes, causing febrile illness as well as acute or chronic arthritis. With increasing reports in previously non-endemic regions, it poses an emerging threat to public health and a growing risk to travelers. Despite the recent approval of live-attenuated and virus-like particle-based vaccines, a safe, efficacious, and cost-effective vaccine remains urgently needed. The envelope glycoproteins E1 and E2, which play crucial roles in viral attachment and entry, are the major immunodominant structural proteins and can effectively elicit protective antibodies. We engineered mammalian cells to produce the ectodomains of the E1 and E2 glycoproteins and evaluated the protective efficacy of the resulting vaccine formulations in vivo. A two-dose vaccination regimen elicited high levels of antibodies and provided full protection against lethal challenge in A129 mice, preventing both death and joint swelling. These findings demonstrate the potential of this vaccine candidate against CHIKV and warrant its further development.

[Strategies to address vaccine hesitancy in Brazil: evidence synthesis].

Marques Ana Paula da Costa APDC, Gubert Vanessa Terezinha VT, Dias Adriano da Costa ADC, Gasparoto Antonio Luiz Dal Bello ALDB et al.

Clinical effects of third doses of mRNA COVID-19 vaccines among hemodialysis patients: a nationwide retrospective cohort study.

Cho AJin A, Jeong Seon A SA, Seo Yu Bin YB, Park Hayne Cho HC et al.

Evidence on the effectiveness of third-dose messenger RNA (mRNA) coronavirus disease 2019 (COVID-19) vaccination during the Omicron-dominant period in Asian hemodialysis (HD) patients remains limited. We evaluated the clinical effectiveness of a third mRNA vaccine dose against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, hospitalization, and mortality in Korean HD patients. Using the Korea Disease Control and Prevention Agency-National Health Insurance Service database, we conducted a nationwide cohort study of HD patients aged ≥18 years who received two or three doses of BNT162b2 or mRNA-1273 before January 16, 2022. Study outcomes were SARS-CoV-2 infection, hospitalization, and death. Cox proportional hazards models were used to assess the associations between third-dose vaccination and clinical outcomes. Among 66,389 HD patients (mean age, 65.7 ± 12.9 years; 60.5% male), 55,125 (83.0%) received three vaccine doses and 11,264 (17.0%) received two doses. Receipt of three doses was associated with a significantly lower risk of SARS-CoV-2 infection (adjusted hazard ratio [aHR], 0.58; 95% confidence interval [CI], 0.56-0.60). Among 17,886 patients with SARS-CoV-2 infection, third-dose vaccine recipients had a lower risk of hospitalization (aHR, 0.65; 95% CI, 0.62-0.70) and 30-day mortality (aHR, 0.35; 95% CI, 0.30-0.41) compared with those who received two doses. Receipt of mRNA-1273 as the third dose was associated with lower observed risks of infection and hospitalization than receipt of BNT162b2. A third dose of an mRNA COVID-19 vaccine was associated with lower risks of SARS-CoV-2 infection, hospitalization, and mortality among HD patients during the Omicron-dominant period. These findings support the clinical importance of booster vaccination in this high-risk population.