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Introduction Nearly all existing respiratory syncytial virus (RSV) incidence estimates are based on real-time polymerase chain reaction (RT–PCR) testing of nasal or nasopharyngeal (NP) swabs. Adding testing of additional specimen types to NP swab RT–PCR increases RSV detection. However, prior studies only made pairwise comparisons and the synergistic effect of adding multiple specimen types has not been quantified. We compared RSV diagnosis by NP swab RT–PCR alone versus NP swab plus saliva, sputum, and serology. Methods This was a prospective cohort study over two study periods (27 December 2021 to 1 April 2022 and 22 August 2022 to 11 November 2022) of patients aged ≥ 40 years hospitalized for acute respiratory illness (ARI) in Louisville, KY. NP swab, saliva, and sputum specimens were collected at enrollment and PCR tested (Luminex ARIES platform). Serology specimens were obtained at acute and convalescent timepoints (enrollment and 30–60-day visit). RSV detection rate was calculated for NP swab alone and for NP swab plus all other specimen type/test. Results Among 1766 patients enrolled, 100% had NP swab, 99% saliva, 34% sputum, and 21% paired serology specimens. RSV was diagnosed in 56 (3.2%) patients by NP swab alone, and in 109 (6.2%) patients by NP swab plus additional specimens, corresponding to a 1.95 times higher rate [95% confidence interval (CI) 1.62, 2.34]. Limiting the comparison to the 150 subjects with all four specimen types available (i.e., NP swab, saliva, sputum, and serology), there was a 2.60-fold increase (95% CI 1.31, 5.17) compared to NP swab alone (3.3% versus 8.7%). Sensitivities by specimen type were: NP swab 51%, saliva 70%, sputum 72%, and serology 79%. Conclusions Diagnosis of RSV in adults was several-fold greater when additional specimen types were added to NP swab, even with a relatively low percentage of subjects with sputum and serology results available. Hospitalized RSV ARI burden estimates in adults based solely on NP swab RT–PCR should be adjusted for underestimation.

Background. Currently, there are no licensed vaccines or therapeutics for the prevention or treatment of infection by the highly lethal filoviruses, Ebola virus (EBOV) and Marburg virus (MARV), in humans.We previously had demonstrated the protective efficacy of virus-like particle (VLP)-based vaccines against EBOV and MARV infection in rodents. Methods. To determine the efficacy of vaccination with Ebola VLPs (eVLPs) in nonhuman primates, we vaccinated cynomolgus macaques with eVLPs containing EBOV glycoprotein (GP), nucleoprotein (NP), and VP40 matrix protein and challenged the macaques with 1000 pfu of EBOV. Results. Serum samples from the eVLP-vaccinated nonhuman primates demonstrated EBOV-specific antibody titers, as measured by enzyme-linked immunosorbent assay, complement-mediated lysis assay, and anti-body dependent cell-mediated cytotoxicity assay. CD44+ T cells from eVLP-vaccinated macaques but not from a naive macaque responded with vigorous production of tumor necrosis factor-α after EBOV-peptide stimulation. All 5 eVLP-vaccinated monkeys survived challenge without clinical or laboratory signs of EBOV infection, whereas the control animal died of infection. Conclusion. On the basis of safety and efficacy, eVLPs represent a promising filovirus vaccine for use in humans.

•PCV13 formulated in a multidose vial (MDV) facilitates access to the vaccine.•Immunogenicity and safety of PCV13-MDV in Indian infants and toddlers were evaluated.•PCV13-MDV was safe and well tolerated when given with routine pediatric vaccines.•PCV13-MDV elicited comparable immune responses to single dose formulated PCV13. This phase 4, randomized, open-label, multicenter study in healthy Indian infants and toddlers evaluated the safety, tolerability, and immunogenicity of the 13-valent pneumococcal conjugate vaccine (PCV13) formulated in a multidose vial (MDV) or single prefilled syringe (PFS). Healthy Indian infants (6 weeks of age) were randomized 1:1 to receive either PCV13-MDV or PCV13-PFS concomitant with routine pediatric vaccines. Subjects received a single dose of either PCV13-MDV or PCV13-PFS as a 4-dose schedule (infant series: 1 dose at 6, 10, and 14 weeks of age; toddler dose: 12 months of age). Safety was assessed, including local reactions, systemic events, and adverse events (AEs). Immunogenicity 1 month after both the infant series and toddler dose was measured by concentrations of serotype-specific immunoglobulin G (IgG) antibodies and opsonophagocytic activity titers. Rates and severities of local reactions and systemic events up to 7 days after each dose of either PCV13-MDV or PCV13-PFS were generally similar, with the majority being of mild or moderate severity. PCV13-MDV had a safety profile comparable with PCV13-PFS; both groups experienced a similar frequency of AEs. PCV13-MDV elicited immune responses comparable with those induced by PCV13-PFS. Clear boosting of immune responses after the PCV13-MDV toddler dose was observed; ≥96% of subjects showed serotype-specific IgG concentrations at or above the defined thresholds 1 month after the PCV13-MDV toddler dose. PCV13-MDV was safe, well tolerated, and immunogenic in healthy Indian infants and toddlers when coadministered with routine pediatric vaccinations. Safety and immunogenicity of PCV13-MDV was comparable with PCV13-PFS. Clinicaltrials.gov: NCT03548337.

Professional antigen-presenting dendritic cells (DCs) are critical in regulating T cell immune responses at both systemic and mucosal sites. Many Lactobacillus species are normal members of the human gut microflora and most are regarded as safe when administered as probiotics. Because DCs can naturally or therapeutically encounter lactobacilli, we investigated the effects of several well defined strains, representing three species of Lactobacillus on human myeloid DCs (MDCs) and found that they modulated the phenotype and functions of human MDCs. Lactobacillus-exposed MDCs up-regulated HLA-DR, CD83, CD40, CD80, and CD86 and secreted high levels of IL-12 and IL-18, but not IL-10. IL-12 was sustained in MDCs exposed to all three Lactobacillus species in the presence of LPS from Escherichia coli, whereas LPS-induced IL-10 was greatly inhibited. MDCs activated with lactobacilli clearly skewed CD4+and CD8+T cells to T helper 1 and Tc1 polarization, as evidenced by secretion of IFN-γ, but not IL-4 or IL-13. These results emphasize a potentially important role for lactobacilli in modulating immunological functions of DCs and suggest that certain strains could be particularly advantageous as vaccine adjuvants, by promoting DCs to regulate T cell responses toward T helper 1 and Tc1 pathways.

This randomized trial of the BNT162b2 vaccine involved 2260 adolescents 12 to 15 years of age. Similar levels of antibody to SARS-CoV-2 were elicited in the 12-to-15-year-old participants and in 16-to-25-year-old participants in a parallel trial. Among participants with no evidence of previous infection, no cases of Covid-19 were diagnosed in vaccine recipients, as compared with 16 cases in placebo recipients.

Background/Objectives: We aimed to determine safe and immunogenic RSVpreF vaccine dose levels for further clinical development in 2–<18 year olds. Methods: The phase 1, age-descending, open-label Picasso trial evaluated different RSVpreF dose levels in respiratory syncytial virus (RSV)-seropositive 2–<5 year olds and 5–<18 year olds who were either healthy or had chronic medical conditions with increased RSV illness risk. Participants received a single dose of RSVpreF (60 µg or 120 µg dose level). The primary objective was to describe safety and tolerability at each dose level and age group, including frequencies of reactogenicity and adverse events (AEs). The secondary objective was to describe RSV neutralizing antibody responses at each dose level and age group 1 month after vaccination. Results: Overall, 127 participants received RSVpreF 60 µg (2–<5 year olds, n = 20; 5–<18 year olds, n = 35) or 120 µg (n = 24 and n = 48, respectively); 54% were male and 69% were White. Local reactions and systemic events were reported in 17–20% and 33–45% of 2–<5 year olds, respectively, and 49–56% and 52–60% of 5–<18 year olds; most were mild or moderate in severity. AEs were reported in 13–15% of 2–<5 year olds and 8–14% of 5–<18 year olds. No AEs leading to withdrawal or vaccine-related serious AEs were reported. RSV-A and RSV-B neutralizing titer geometric mean fold rises from before to 1 month after vaccination with RSVpreF 60 and 120 µg, which were 17.7–20.6 and 42.8–39.8, respectively, in 2–<5 year olds, and 19.0–23.5 and 20.3–20.3, respectively, in 5–<18 year olds. Conclusions: RSVpreF was safe, well tolerated, and elicited immune responses in RSV-seropositive 2–<18-year-old participants, supporting further clinical development in this pediatric population, including those with chronic conditions.

Current methods for inactivating filoviruses are limited to high doses of irradiation or formalin treatment, which may cause structural perturbations that are reflected by poor immunogenicity. In this report, we describe a novel inactivation technique for Zaire Ebola virus (ZEBOV) that uses the photoinduced alkylating probe 1,5-iodonaphthylazide (INA). INA is incorporated into lipid bilayers and, when activated by ultraviolet irradiation, alkylates the proteins therein. INA treatment of ZEBOV resulted in the complete loss of infectivity in cells. Results of electron microscopy and virus-capture assays suggested the preservation of conformational surface epitopes. Challenge with 50,000 pfu of INA-inactivated, mouse-adapted ZEBOV did not cause disease or death in mice. A single vaccination with INA-inactivated ZEBOV (equivalent to 5×104 pfu) protectedmice against lethal challenge with 1000 pfu of ZEBOV. INA-inactivated virus induced a protective response in 100% of mice when administered 3 days before challenge. Thus, INA may have significant potential for the development of vaccines and immunotherapeutics for filoviruses and other enveloped viruses.

Filoviruses subvert the human immune system in part by infecting and replicating in dendritic cells (DCs). Using gene arrays, a phenotypic profile of filovirus infection in human monocyte-derived DCs was assessed. Monocytes from human donors were cultured in GM-CSF and IL-4 and were infected with Ebola virus Kikwit variant for up to 48 h. Extracted DC RNA was analyzed on SuperArray's Dendritic and Antigen Presenting Cell Oligo GEArray and compared to uninfected controls. Infected DCs exhibited increased expression of cytokine, chemokine, antiviral, and anti-apoptotic genes not seen in uninfected controls. Significant increases of intracellular antiviral and MHC I and II genes were also noted in EBOV-infected DCs. However, infected DCs failed to show any significant difference in co-stimulatory T-cell gene expression from uninfected DCs. Moreover, several chemokine genes were activated, but there was sparse expression of chemokine receptors that enabled activated DCs to home to lymph nodes. Overall, statistically significant expression of several intracellular antiviral genes was noted, which may limit viral load but fails to stop replication. EBOV gene expression profiling is of vital importance in understanding pathogenesis and devising novel therapeutic treatments such as small-molecule inhibitors.

Background Marburg virus (MARV) causes acute hemorrhagic fever that is often lethal, and no licensed vaccines are available for preventing this deadly viral infection. The immune mechanisms for protection against MARV are poorly understood, but previous studies suggest that both antibodies and T cells are required. In our study, we infected BALB/c mice with plaque-purified, nonlethal MARV and used overlapping peptides to map H2 d -restricted CD8+ T-cell epitopes. Methods Splenocytes from mice infected with nonlethal MARV were harvested and stimulated with multiple overlapping 15-mer peptide pools, and reactive CD8+ T cells were evaluated for antigen specificity by measuring upregulation of CD44 and interferon-γ expression. After confirming positive reactivity to specific 15-mer peptides, we used extrapolated 9-mer epitopes to evaluate the induction of cytotoxic T-cell responses and protection from lethal MARV challenge in BALB/c mice. Results We discovered a CD8+ T-cell epitope within both the MARV glycoprotein (GP) and nucleoprotein (NP) that triggered cytotoxic T-cell responses. These responses were also protective when epitope-specific splenocytes were transferred into naïve animals. Conclusion Epitope mapping of MARV GP, NP, and VP40 provides the first evidence that specific MARV-epitope induction of cellular immune responses is sufficient to combat infection. Establishment of CD8+ T-cell epitopes that are reactive to MARV proteins provides an important research tool for dissecting the significance of cellular immune responses in BALB/c mice infected with MARV.

Safe RSV vaccine development has challenged the medical community since a formalin-killed RSV vaccine caused disease exacerbation in the 1960s. Disease was replicated using the bovine RSV system in one of two studies. The studies differed in viral protein dose and length of time between vaccination and infection. Disease exacerbation occurred in study 2 (previously reported). We hypothesized that low protein concentration in study 2’s vaccine stimulated a TH2/IgE response that enhanced disease. BRSV-specific IgG1, IgG2, and IgE were measured by ELISA/Western blot from vaccinated/infected, vaccinated/mock infected, mock vaccinated/infected calves in both studies. Results revealed that study 2 calves produced more IgE, particularly to the nucleoprotein (N); IgE among study 2 calves correlated with high clinical scores. In contrast, study 1 calves showed stronger IgG responses to viral proteins.