influenza vaccine

Influenza Vaccine Effectiveness Across Nutritional Status Categories in Patients Hospitalized With Acute Heart Failure: A Secondary Analysis of the PANDA II Trial.

Liu Xinru X, Wang Zhiyan Z, Hua Chang C, Wu Yanfang Y et al.

Porcine Adenovirus-Based Viral Vectors for Swine Vaccines: A Scoping Review and Future Perspectives.

Sthitmatee Nattawooti N, Suanpat Karnrawee K, Sington Yupa Y, Muenthaisong Anucha A et al.

Porcine adenoviruses (PAdVs) are promising but still underdeveloped viral-vector platforms for swine vaccine development. Compared with human adenovirus-based vectors, PAdV vectors may offer potential advantages in host association, veterinary relevance, and mucosal delivery while avoiding direct reliance on common human adenovirus backbones. This review summarizes current knowledge on PAdV biology, vector engineering, vaccine applications, immune responses, translational challenges, and future priorities. Early studies showed that recombinant PAdV vectors can express heterologous antigens from important swine pathogens, including classical swine fever virus, pseudorabies virus, and transmissible gastroenteritis virus. The strongest direct proof-of-concept evidence comes from recombinant PAdV expressing classical swine fever virus E2/gp55, which induced neutralizing antibodies and protection in pigs. Comparative adenovirus-vectored swine vaccine studies support the broader feasibility of adenoviral antigen delivery for porcine reproductive and respiratory syndrome, porcine epidemic diarrhea, swine influenza, and African swine fever, but these data should not be interpreted as direct validation of PAdV for these diseases. Major gaps remain in anti-PAdV immunity, genetic stability, biosafety, shedding, target-animal safety, DIVA compatibility, manufacturing, and regulatory readiness. Recent advances in PAdV-5 reverse genetics provide new opportunities for modern vector design.

Perception of virus effects and vaccination among people with multiple sclerosis in Saudi Arabia.

Alnajashi Hind H, Basheikh Khadijah Ibraheem KI, Alqurayqiri Bushra Obaidallah A BOA, Albar Fayzah Shaikh FS et al.

People with multiple sclerosis (pwMS) are at increased risk of infection due to immune dysregulation and exposure to disease-modifying therapies (DMTs). Despite this risk, real-world vaccine uptake remains inconsistent. This study evaluated vaccination readiness, counseling practices, and infection-related perceptions among pwMS in Saudi Arabia. A cross-sectional survey was conducted among adults with MS (n = 204) recruited using non-probability (convenience) sampling from tertiary-care clinical and community-based sources. The survey assessed demographic characteristics, vaccination attitudes and uptake, counseling experiences, perceptions of infection risk related to MS and DMTs, and awareness of Epstein-Barr virus (EBV). Internal consistency of multi-item measures was acceptable (Cronbach's α = 0.72). Descriptive statistics were used to summarize outcomes. The cohort was relatively young (mean age 35.7 years), with two-thirds aged 25-44 years (25-34 years: 38.2%; 35-44 years: 36.8%). Most participants held a bachelor's degree (66.7%). Attitudes toward routine vaccination were frequently non-committal: 47.6% were somewhat or very likely to vaccinate, 33.8% were neutral, and 18.6% were somewhat or very unlikely; separately, 60.8% agreed or somewhat agreed that routine vaccines might be harmful for pwMS. COVID-19 vaccination uptake was high (72.5%), whereas influenza vaccination was low (30.9%). Uptake of other adult vaccines, including hepatitis B, meningococcal, herpes zoster, and human papillomavirus vaccines, was < 10% for each. Perceived infection vulnerability was substantial, with 62.7% expressing concern about viral infections due to MS and 71.1% believing that DMTs increased susceptibility, consistent with 59.4% receiving high-efficacy DMTs. Awareness of EBV was limited: 26.5% had heard of EBV, 16.6% perceived an MS-EBV association, and 21.1% were aware of possible causality. Nearly half of participants (49.0%) were undecided about a hypothetical EBV vaccine, while approximately 44% expressed willingness to receive it. Counseling gaps were evident, as only 32.8% reported any discussion about vaccination with clinicians; counseling prior to DMT initiation and during ongoing treatment was reported by 16.2% and 19.1%, respectively. In a young and highly educated cohort of pwMS in Saudi Arabia, vaccine hesitancy and counseling gaps persist despite high perceived infection risk. These findings highlight the need for structured and routine vaccine counseling, particularly at MS diagnosis and before initiating high-efficacy DMTs, to improve uptake of influenza and other recommended adult vaccines in MS clinics.

H3 Subtype Avian Influenza Virus: Ecology, Cross-Species Evolution, and Public Health Threats.

Cheng Kaihui K, Yu Zhijun Z

H3 subtype avian influenza virus (AIV) is one of the most widely distributed and frequently detected low-pathogenicity avian influenza viruses (LPAIVs) in wild birds and poultry worldwide. Wild waterfowl are the natural reservoir of this virus. In recent years, driven by frequent genetic reassortment and continuous evolution, H3 subtype AIV has expanded its host range to include various mammalian species-dogs, cats, horses, seals, pigs (experimental infection), and humans. Among these, the H3N8 subtype shows the broadest cross-species transmissibility, having established sustained transmission lineages in horses and dogs, while also causing sporadic infections in seals and humans. Avian-origin H3N2 canine influenza virus has circulated stably in dog populations across Asia and North America for nearly two decades. Between 2022 and 2023, China reported three human cases of H3N8 subtype AIV infection, one of which was fatal (Guangdong, March 2023), indicating that this virus poses a potential zoonotic transmission risk. Novel triple-reassortant strains, including genotype G25 of H3N8 and H3N3, first detected in chicken flocks in late 2022, have continued to emerge. Their HA genes originate from H3 subtype viruses of wild bird or chicken origin, whereas their internal gene segments are predominantly acquired from H9N2 subtype AIV, resulting in enhanced mammalian adaptability. This review summarizes the global epidemiology of H3 subtype AIV (covering wild birds, poultry, and live poultry markets), its genetic evolution and reassortment patterns, and the molecular mechanisms underlying cross-species transmission. This review particularly highlights the regulatory roles of key amino acid mutations-such as PB2-D701N, M1-M192V, and HA-Q226L/G228S-in receptor binding preference, polymerase activity, and pathogenicity. This review also summarizes recent advances in detection techniques (multiplex RT-PCR, quantum dot-based immunochromatographic strips, RT-RAA, and CRISPR-Cas13a) and vaccine development (inactivated, adenovirus-vectored, and mRNA vaccines). Key prevention and control challenges-including covert circulation, surveillance gaps, and limited subtyping diagnostic capacity at primary laboratories-are also discussed. This review proposes that H3 subtype AIV should be recognized as a potential zoonotic threat warranting continued surveillance, although no evidence of sustained human-to-human transmission has been documented to date. Better understanding of cross-species mechanisms, stronger surveillance and early warning, and evidence-based control strategies are needed to inform future risk assessment.