Influenza A has two hemagglutinin groups, with stronger cross-immunity to reinfection within than between groups. Here, we explore the implications of this heterogeneity for proposed cross-protective influenza vaccines that may offer broad, but not universal, protection. While the development goal for the breadth of human influenza A vaccine is to provide cross-group protection, vaccines in current development stages may provide better protection against target groups than non-target groups. To evaluate vaccine formulation and strategies, we propose a novel perspective: a vaccine population-level target product profile (PTPP). Under this perspective, we use dynamical models to quantify the epidemiological impacts of future influenza A vaccines as a function of their properties. Our results show that the interplay of natural and vaccine-induced immunity could strongly affect seasonal subtype dynamics. A broadly protective bivalent vaccine could lower the incidence of both groups and achieve elimination with sufficient vaccination coverage. However, a univalent vaccine at low vaccination rates could permit a resurgence of the non-target group when the vaccine provides weaker immunity than natural infection. Moreover, as a proxy for pandemic simulation, we analyze the invasion of a variant that evades natural immunity. We find that a future vaccine providing sufficiently broad and long-lived cross-group protection at a sufficiently high vaccination rate, could prevent pandemic emergence and lower the pandemic burden. This study highlights that as well as effectiveness, breadth and duration should be considered in epidemiologically informed TPPs for future human influenza A vaccines.

Severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) and influenza viruses have spread around the world at an unprecedented rate. Despite multiple vaccines, new variants of SARS-CoV-2 and influenza have caused a remarkable level of pathogenesis. The development of effective antiviral drugs to treat SARS-CoV-2 and influenza remains a high priority. Inhibiting viral cell surface attachment represents an early and efficient means to block virus infection. Sialyl glycoconjugates, on the surface of human cell membranes, play an important role as host cell receptors for influenza A virus and 9-O-acetyl-sialylated glycoconjugates are receptors for MERS, HKU1 and bovine coronaviruses. We designed and synthesized multivalent 6\'-sialyllactose-counjugated polyamidoamine dendrimers through click chemistry at room temperature concisely. These dendrimer derivatives have good solubility and stability in aqueous solutions. SPR, a real-time analysis quantitative method for of biomolecular interactions, was used to study the binding affinities of our dendrimer derivatives by utilizing only 200 micrograms of each dendrimer. Three SARS-CoV-2 S-protein receptor binding domain (wild type and two Omicron mutants) bound to multivalent 9-O-acetyl-6\'-sialyllactose-counjugated and 6\'-sialyllactose-counjugated dendrimers bound to a single H3N2 influenza A virus\'s HA protein (A/Hong Kong/1/1968), the SPR study results suggest their potential anti-viral activities.

BACKGROUND: Through the comparison of the demographic, epidemiological, and clinical characteristics of hospital human influenza (influenza A (H1N1) pdm09, H3N2, and B)-related and hospitalized avian-origin influenza A (H7N9)-related viral pneumonia patients, find the different between them.
METHODS: A retrospective study was conducted in hospitalized influenza-related viral pneumonia patients.
RESULTS: Human influenza A-related patients in the 35-49-year-old group were more than those with B pneumonia patients (p = 0.027), and relatively less in the ≥ 65-year-old group than B pneumonia patients (p = 0.079). The proportion of comorbid condition to human influenza A pneumonia was 58%, lower than B pneumonia and H7N9 pneumonia patients (78% vs. 77.8%; p = 0.013). The proportion of invasive mechanical ventilation (IMV), lymphocytopenia, elevated lactate dehydrogenase to hospitalized human influenza A-related viral pneumonia patients was higher than B pneumonia patients (p < 0.05), but lower than H7N9 pneumonia patients (p < 0.05). In the multivariate analysis, pulmonary consolidation (odds ratio (OR): 13.67; 95% confidence interval (CI) 1.54-121.12; p = 0.019) and positive bacterial culture (sputum) (OR: 7.71; 95% CI 2.48-24.03; p < 0.001) were independently associated with IMV, while shock (OR: 13.16; 95% CI 2.06-84.07; p = 0.006), white blood cell count > 10,000/mm3 (OR: 7.22; 95% CI 1.47-35.58; p = 0.015) and positive bacterial culture(blood or sputum) (OR: 6.27; 95% CI 1.36-28.85; p = 0.018) were independently associated with death in the three types hospitalized influenza-related viral pneumonia patients.
CONCLUSIONS: Hospital influenza B-related viral pneumonia mainly affects the elderly and people with underlying diseases, while human influenza A pneumonia mainly affects the young adults; however, the mortality was similar. The hospitalized human influenza A-related viral pneumonia patients was severer than B pneumonia patients, but milder than H7N9 pneumonia patients. Pulmonary consolidation and positive bacterial culture (sputum) were independently associated with IMV, while shock, white blood cell count > 10,000/mm3, and positive bacterial culture (blood or sputum) were independently associated with death to three types hospitalized influenza-related viral pneumonia patients.