Antiviral activity of an ACE2-Fc fusion protein against SARS-CoV-2 and its variants.

SARS-CoV-2 has continued spreading around the world in recent years since the initial outbreak in 2019, frequently developing into new variants with greater human infectious capacity. SARS-CoV-2 and its mutants use the angiotensin-converting enzyme 2 (ACE2) as a cellular entry receptor, which has triggered several therapeutic strategies against COVID-19 relying on the use of ACE2 recombinant proteins as decoy receptors. In this work, we propose an ACE2 silent Fc fusion protein (ACE2-hFcLALA) as a candidate therapy against COVID-19. This fusion protein was able to block the binding of SARS-CoV-2 RBD to ACE2 receptor as measured by ELISA and flow cytometry inhibition assays. Moreover, we used classical neutralization assays and a progeny neutralization assay to show that the ACE2-hFcLALA fusion protein is capable of neutralizing the authentic virus. Additionally, we found that this fusion protein was more effective in preventing in vitro infection with different variants of interest (alpha, beta, delta, and omicron) compared to the D614G strain. Our results suggest the potential of this molecule to be used in both therapeutic and preventive settings against current and emerging mutants that use ACE2 as a gateway to human cells.

PtpA protein from Mycobacterium avium subsp. paratuberculosis as a potential marker of rheumatoid arthritis in humans.

Studies have noted the connection between Mycobacterium avium subspecies paratuberculosis (MAP) and autoimmunity. MAP is an intracellular pathogen that infects and multiplies in macrophages. To overcome the hostile environment elicited by the macrophage, MAP secretes a battery of virulence factors to neutralize the toxic effects of the macrophage. One of the virulence factors is the Protein Tyrosine Phosphatase A (PtpA), a protein secreted by MAP that interferes in the phago-lysosome fusion, rendering the pathogen unnoticed in the cytoplasm of the macrophage. This study aimed to assess the presence of PtpA antibodies in the sera of Mexican individuals with rheumatoid arthritis (RA) and investigate its possible use as a biomarker for disease activity. We compared RA patients (n = 100) to control subjects (CS) (n = 100) by assessing specific immune responses to PtpA (the antigen) by an indirect ELISA method. Results showed a significant difference in PtpA levels between RA and CS, with RA patients having a median OD of 0.4645 compared to 0.1372 in CS. Antibodies against PtpA were present in 95% of RA patients and 16% of CS (AUC = 0.9163, p = 0.0001). Male control subjects showed higher PtpA reactivity than female CS. The Disease Activity Score (DAS-28) analysis showed that individuals with moderate to high disease activity had lower levels of PtpA reactivity. The results suggest a potential connection between RA and MAP infection.

Early neutrophil activation and NETs release in the pristane-induced lupus mice model.

BACKGROUND: NETosis is recognized as an important source of autoantigens. Therefore, we hypothesized whether the pristane-induced lupus mice model shows early activation of neutrophils, the presence of low-density granulocytes (LDGs), and neutrophil extracellular traps (NETs) release, which could contribute to the development of a lupus phenotype. METHODS: Twelve female wild-type Balb/c mice were intraperitoneally injected with pristane (n = 6; pristane group) or saline (n = 6; control group). Five days after the injection, blood, peritoneal lavage, bone marrow, and spleen samples were collected for flow cytometry analyses of activated neutrophils (Ly6G+CD11b+), LDGs (CD15+CD14low), and NETs release (Sytox Green+). RESULTS: The pristane-induced mice group had a significantly increased number of blood activated neutrophils and LDGs as well as NETs released by these cells compared to the saline-injected control group and the basal values determined 12 days before the injection. The pristane group also had a significantly increased number of activated neutrophils, LDGs, and NETs released compared to the control group for the peritoneal lavage and bone marrow, except total cell count in spleen. CONCLUSIONS: We demonstrated early changes in the innate immune response such as an increased number of activated neutrophils and LDGs and mainly increased NETosis in the pristane-induced mice model which may be considered as the primary event triggering lupus development.

Zebrafish Larvae Microinjection and Automated Fluorescence Microscopy for Studying Klebsiella pneumoniae Infection and the Host Immune Response.

Studying host-pathogen interactions is essential for understanding infectious diseases and developing possible treatments, especially for priority pathogens with increased virulence and antibiotic resistance, such as Klebsiella pneumoniae. Over time, this subject has been approached from different perspectives, often using mammal host models and invasive endpoint measurements (e.g., sacrifice and organ extraction). However, taking advantage of technological advances, it is now possible to follow the infective process by noninvasive visualization in real time, using optically amenable surrogate hosts. In this line, this chapter describes a live-cell imaging approach to monitor the interaction of K. pneumoniae and potentially other bacterial pathogens with zebrafish larvae in vivo. This methodology is based on the microinjection of fluorescent bacteria into the otic vesicle, followed by time-lapse observation by automated fluorescence microscopy with environmental control, monitoring the dynamics of immune cell recruitment, bacterial load, and larvae survival.

Evaluation of nonpolar lipid extract antigen-based enzyme-linked immunosorbent assay for the serodiagnosis of tuberculosis.

This study assessed the diagnostic potential of nonpolar lipid extracts in enzyme-linked immunosorbent assays (ELISAs) for tuberculosis (TB) serodiagnosis. Nonpolar lipid extracts were harvested from Mycobacterium tuberculosis (Mtb) knockout in mce1 operon (∆mce1) and its parental wild type (WT) strains. IgM and IgG anti-nonpolar lipid serum levels were measured in TB patients (n=45), healthy individuals with positive (n=22) and negative (n=44) interferon-gamma release assay (IGRA) results, and symptomatic respiratory (SR) patients with negative TB tests (n=9). IgG anti-WT lipid distinguished TB patients from IGRA-positive individuals with 60% sensitivity and 77.3% specificity. Conversely, IgG anti-∆mce lipid levels didn't vary significantly across groups. Interestingly, most SR patients exhibited significantly higher IgM and IgG anti-WT lipid titers than the IGRA-positive and -nega groups. While the overall diagnostic potential of Mtb nonpolar lipids was limited, the impaired immunogenecity of Δmce1 lipid extract suggests that some missing lipid classes in this extract can potentially induce antibody production in TB patients.

Green guaje (Leucaena leucocephala) and pigmented guaje (Leucaena esculenta) as sources of antioxidant and immunomodulatory peptides.

In recent years, there has been a growing interest in plant-based diets, particularly legumes, as a sustainable and healthy dietary choice. This study breaks new ground by investigating the effects of simulated gastrointestinal digestion on green (Leucaena leucocephala) and pigmented (Leucaena esculenta) guaje proteins. We evaluated the antioxidant and immunomodulatory properties of ultrafiltered fractions resulting from digestion in a macrophage model. Both fractions showed promising potential as radical scavengers. The fraction <5 kDa from pigmented guaje, even at the lowest doses tested, significantly (p < 0.05) inhibited the release of pro-inflammatory cytokines TNF-α and IL-6, and demonstrated an immunomodulatory effect by reducing the levels of ROS and NO. These findings suggest that green and pigmented guaje could be a valuable source of bioactive peptides, potentially used as a coadjutant for treating and preventing oxidative stress and inflammation-associated non-communicable diseases through the utilization of underutilized legumes.

Acute low temperature and lipopolysaccharide differentially modulated the innate immune and antioxidant responses in a subtropical fish, the pacu (Piaractus mesopotamicus).

Exogenous factors such as low water temperature can be stressful and elicit negative immune system effects, especially for fish, which are ectothermic. Stress and immune responses require energy overload, which can affect the cellular redox balance, causing oxidative damage. These overall responses impair the animal's health and negatively affect fish farming. To evaluate indicators of stress, immune and antioxidant systems, and oxidative stress responses in fish during thermal challenge, the present study reduced the water temperature from 29.5 °C to 16 °C and then inoculated pacu (Piaractus mesopotamicus) with lipopolysaccharide (LPS) from Escherichia coli. Our results revealed that acute exposure to low water temperature itself increased blood glucose, impaired the serum lysozyme concentration and increased GSH-Px activity. There was an interaction effect between low temperature and LPS inoculation. After LPS inoculation, leukocytes were initially activated (3 h); glucose levels increased (3 h); GST activity initially decreased (3 h) but then increased (6 h); SOD, CAT and GSH-Px activities decreased; and lysozyme activity remained depressed in fish subjected to cold shock. The results showed that thermal and immunological challenges impaired the maintenance of leucocyte activation and compromised the pacu oxidant response. The overall response of pacu to thermal challenge indicates that the species proved to be acutely sensitive to a drop in water temperature, reducing its ability to maintain homeostasis, especially when subjected to immunological challenge.

Impact of COVID-19 Pandemic on HIV Testing, Recent Infections, and Annualized Incidence Among Cisgender Men Who Have Sex With Men and Transgender Women in Brazil.

BACKGROUND: The COVID-19 pandemic had great impact on HIV care and prevention worldwide, including in Brazil. We compared HIV testing, recent infection, and annualized incidence according to the COVID-19 pandemic period among cisgender men who have sex with men (MSM) and transgender women (TGW). SETTING: HIV and sexually transmitted infection testing, prevention, and treatment referral service in Rio de Janeiro, Brazil. METHODS: We used Maxim HIV-1 Limiting Antigen Avidity EIA as part of a recent infection testing algorithm to identify recent HIV infection cases and estimate annualized HIV incidences in the pre- (March 2018-February 2020) and post-COVID-19 pandemic onset period (March 2020-January 2022). Multivariable logistic regression model assessed factors associated with recent HIV infection. RESULTS: Among 3814 MSM and 776 TGW, 593 (12.9%) tested positive for HIV and 119 (2.6%) were identified as having recent infection. Percentage of recent HIV infection did not differ between the COVID-19 periods. Overall annualized HIV incidence rates were 6.0% (95% confidence interval [CI]: 4.2 to 7.7) and 6.6% (95% CI: 4.3 to 9.0) in the pre- and post-COVID-19 periods, respectively. During the post-COVID-19 period, higher incidence rates were observed among TGW (8.4% [95% CI: 2.9 to 13.9]), those aged 18-24 years (7.8% [95% CI: 4.0 to 11.7]), of Black race (7.9% [95% CI: 3.8 to 12.0]), and those with <12 years of schooling (7.8% [95% CI: 4.8 to 10.8]). Compared to the pre-COVID-19 period, incidence rates were significantly higher in the post-COVID-19 period for those aged >30 years and TGW, while being lower for those with more years of schooling. CONCLUSION: HIV incidence estimates remain high among MSM and TGW in Brazil, especially among the most vulnerable. The consequences of the COVID-19 pandemic on the HIV epidemic will likely persist and contribute to worsening HIV outcomes.

Impact of histopathological and serological assessments on early diagnosis of leprosy relapse.

This study aimed to identify laboratory factors predicting leprosy relapse (LR) after multi-drug therapy (MDT). A case-control study included 80 patients treated with MDT at a national reference center over 12 years. The Relapse Group had 40 patients who relapsed after an average of 89.2 months post-MDT, while the Control Group had 40 patients who remained asymptomatic for an average of 113.1 months. Significant predictors of LR included neural/perineural lymphocytic infiltrate (OR = 4.67; p = 0.0076) and foamy granulomas (OR = 15.55; p = 0.0005), increasing odds by 4.7 and 15.6 times, respectively. The Relapse Group had a mean histological bacillary index (hBI) of 3.23+ compared to 1.8 in the Control Group (p = 0.004). An hBI ≥3+ had 72% sensitivity and 65% specificity for detecting LR (AUC = 0.72; p = 0.0002). Elevated anti-phenolic glycolipid I (anti-PGL-I) IgM antibody levels (ELISA index, EI ≥1) were also associated with LR (OR = 4.67; p = 0.0031). An EI ≥3.6 had 71% sensitivity and 62% specificity (AUC = 0.70; p = 0.0012). Multivariate analysis indicated that neural/perineural infiltrate, foamy granulomas, hBI ≥ 1+, and EI ≥ 1 significantly predicted LR, with up to 94.32% probability. Conclusively, these factors can identify individuals at high probability of LR after MDT.

Effect of refrigeration, room temperature, and processing time on serum immunofluorescent antibody titers for Sarcocystis neurona.

BACKGROUND: Evaluating antibody titers for Sarcocystis neurona for the diagnosis of equine protozoal myeloencephalitis from serum samples is a common practice. However, ensuring timely and proper refrigeration is not always possible. OBJECTIVES: To evaluate immunofluorescent antibody (IFA) titers for S. neurona from serum samples stored at room temperature and 4°C. SAMPLES: Twenty-two serum samples. METHODS: Prospective longitudinal study. Two serum aliquots of 1 mL each were stored at room temperature (20-23.3°C) and 4°C. The unrefrigerated aliquot was immediately tested for IFA titers. Both aliquots were retested on Days 5 and 10 after collection. A paired t test was used to compare IFA titers at different time points. RESULTS: There was no significant difference between IFA titers from baseline with those stored at room temperature at Days 5 (P = .741, 95% CI [-56.83, 78.65]), 10 (P = .677, 95% CI [-50.01, 75.46]), and between 5 and 10 days (P = 0.949, 95% CI [-57.50, 61.14]). There was no significant difference from baseline with those stored at 4°C for Days 5 (P = .964, 95% CI [-81.81, 85.45]), 10 (P = 0.573, 95% CI [-109.4, 62.15]), and between 5 and 10 days (P = .5, 95% CI [-102.6, 51.67]). There was no statistical difference between samples stored at room temperature and 4°C (P = .688, CI [-55.51, 37.33]) on Days 5 and 10 (P = .104, CI [-80.8, 8.07]). CONCLUSIONS AND CLINICAL IMPORTANCE: Immunofluorescent antibody test titers for S. neurona are stable for up to 10 days at room temperature and 4°C.

Therapeutic BCG vaccine protects against long COVID: The BATTLE randomized clinical trial.

BACKGROUND: Bacillus Calmette-Guérin (BCG) injected during the COVID-19 convalescence period was safe and enhanced recovery from anosmia and dysgeusia in the acute phase. OBJECTIVES: To report the long-term results of the BATTLE trial, BCG vaccine in adults with mild COVID-19. METHODS: Design: Double-blind, placebo-controlled, randomized (1:1) clinical trial. INTERVENTION: BCG intradermal vaccine and placebo. PATIENTS: A total of 157 BCG and 142 placebo recipients participated in the 6-month follow-up, and 97 BCG and 95 placebo recipients participated in the 12-month follow-up. MEASUREMENTS: Long COVID symptoms and mechanistic analyses. RESULTS: BCG reduced hearing problems at 6 months (odds ratio [OR] = 0.26) and sleeping, concentration, memory, and vision problems at 12 months (OR = 0.45, 0.36, 0.38, and 0.36, respectively). Sensitivity analyses confirmed that long COVID-19 symptoms were reduced at the 6- and 12-month follow-ups (p = 0.010 and 0.031, respectively). BCG's crossover interaction paradoxically increased hair loss in women and decreased it in men at 6 months (p = 0.032). BCG immunomodulation is likely mediated through inhibition of Fas ligand expression in the blood and increased induction of IL6, IL10, interferon-induced transmembrane protein 3, and angiotensin-converting enzyme 2 in cultured human macrophages. CONCLUSION: Long-term follow-up of the BATTLE trial participants revealed that BCG protects against long COVID development if administered within the COVID-19 convalescence period. The response to BCG was subject-specific, including a paradoxical crossover interaction based on sex. LIMITATIONS: Not tested for previous mycobacterial exposure; loss to follow-up, particularly at 12 months.

Quantitative and qualitative analysis of seroconversion after one year of vaccination with inactivated SARS-CoV-2 vaccine (CoronaVac®) in healthcare workers: Cross-sectional analytical study.

A descriptive study was carried out with health professionals in Sao Paulo city. Were included individuals vaccinated with 2 doses of the inactivated vaccine. Demographic, clinical and vaccination information was obtained from professionals with or without comorbidities. Two serological assays were used to identify the presence and quantity of anti-Spike IgG in serum samples. 433 healthy healthcare professionals were included and 58.9 % completed the 4 clinical stages of serological assessment. Among adults and elderly people, 25.2 % had chronic diseases (hypertension 50.5 %, diabetes 10 % and obesity 6.5 %). Most individuals have 95 % protection in the first 3 months after the second dose, and 67.68 % protection after 6 months. Total antibodies ranged from 3 to 10 on the reactivity index, and the anti-RBD IgG levels were high. CoronaVac has a 94 % seroconversion rate after 2 doses and can prevent serious cases and outbreaks of the disease, if used on a large scale.

SNX5 promotes antigen presentation in B cells by dual regulation of actin and lysosomal dynamics.

B cells rapidly adapt their endocytic pathway to promote the uptake and processing of extracellular antigens recognized through the B-cell receptor (BCR). The mechanisms coupling changes in endomembrane trafficking to the capacity of B cells to screen for antigens within lymphoid tissues remain unaddressed. We investigated the role of SNX5, a member of the sorting nexin family, which interacts with endocytic membranes to regulate vesicular trafficking and macropinocytosis. Our results show that in steady state, B cells form SNX5-rich protrusions at the plasma membrane, which dissipate upon interaction with soluble antigens, whereas B cells activated with immobilized antigens accumulate SNX5 at the immune synapse where it regulates actin-dependent spreading responses. B cells silenced for SNX5 exhibit enlarged lysosomes, which are not recruited to the synaptic membrane, decreasing their capacity to extract immobilized antigens. Overall, our findings reveal that SNX5 is critical for actin-dependent plasma membrane remodeling in B cells involved in antigen screening and immune synapse formation, as well as endolysosomal trafficking required to promote antigen extraction and presentation.

T cells regulate intestinal motility and shape enteric neuronal responses to intestinal microbiota.

How the gut microbiota and immune system maintain intestinal homeostasis in concert with the enteric nervous system (ENS) remains incompletely understood. To address this gap, we assessed small intestinal transit, enteric neuronal density, enteric neurogenesis, intestinal microbiota, immune cell populations and cytokines in wildtype and T-cell deficient germ-free mice colonized with specific pathogen-free (SPF) microbiota, conventionally raised SPF and segmented filamentous bacteria (SFB)-monocolonized mice. SPF microbiota increased small intestinal transit in a T cell-dependent manner. SPF microbiota increased neuronal density in the myenteric and submucosal plexuses of the ileum and colon, similar to conventionally raised SPF mice, independently of T cells. SFB increased neuronal density in the ileum in a T cell-dependent manner, but independently of T cells in the colon. SPF microbiota stimulated enteric neurogenesis (Sox2 expression in enteric neurons) in the ileum in a T cell-dependent manner, but in the colon this effect was T cell-independent. T cells regulated nestin expression in the ENS. SPF colonization increased Th17 cells, RORγT+ Treg cells, and IL-1ß and IL-17A levels in the ileum and colon. By neutralizing IL-1ß and IL-17A, we observed that they control microbiota-mediated enteric neurogenesis but were not involved in the regulation of motility. Together, these findings provide new insights into the microbiota-neuroimmune dialog that regulates intestinal physiology.

Design of a multi-epitope vaccine candidate against carrion disease by immunoinformatics approach.

Carrion's disease, caused by the bacterium Bartonella bacilliformis, is a serious public health problem in Peru, Ecuador and Colombia. Currently there is no available vaccine against B. bacilliformis. While antibiotics are the standard treatment, resistant strains have been reported, and there is a potential spread of the vector that transmits the bacteria. This study aimed to design a multi-epitope vaccine candidate against the causative agent of Carrion's disease using immunoinformatics tools. Predictions of B-cell epitopes, as well as CD4+ and CD8+T cell epitopes, were performed from the entire proteome of B. bacilliformis KC583 using the most frequent alleles from Peru, Ecuador, Colombia, and worldwide. B-cell epitopes and T-cell nested epitopes from outer membrane and virulence-associated proteins were selected. Epitopes were filtered out based on promiscuity, non-allergenicity, conservation, non-homology and non-toxicity. Two vaccine constructs were assembled using linkers. The tertiary structure of the constructs was predicted, and their stability was evaluated through molecular dynamics simulations. The most stable construct was selected for molecular docking with the TLR4 receptor. This study proposes a vaccine construct evaluated in silico as a potential vaccine candidate against Bartonella bacilliformis.

Assessment of the BNT162B2 COVID-19 vaccine immune response in Brazilian indigenous adolescents.

BACKGROUND: COVID-19 vaccination of minors is crucial for global pandemic control, especially among indigenous populations, who are often more vulnerable due to limited healthcare resources and communal living settings. OBJECTIVES: To assess the immunogenicity responses of the BNT162b2 vaccine in immunized Brazilian indigenous adolescents. METHODS: A cohort study was conducted with indigenous adolescents aged 12 to 18 years residing in the largest peri-urban indigenous region in Brazil. SARS-CoV-2-specific immune responses were analyzed before (D1) and after (D2) completion of the vaccination schedule. Demographic data were collected using a questionnaire. RESULTS: Of the 129 adolescents invited, 98 (75.96 %) participated in the study. Most were of Guarani ethnicity, single, had lower incomes, and were educated only to the elementary level. Post-vaccination, a statistically significant increase was noted in IgG concentration (24.03 % to 37.02 %). Increases were observed in B lymphocytes (11.88 to 13.92 cells/mm3), memory B cells (13.58 to 15.96 cells/mm3), NK cells (20.23 to 24.08 cells/mm3), and non-classical monocytes (9.23 to 11.34 cells/mm3), while CD8+ T cells decreased (24.41 to 21.69 cells/mm3). Adolescents with prior exposure to the virus showed increased levels of B lymphocytes and CD8+ T cells. No significant changes were observed in other cell subpopulations from exposure to the virus. CONCLUSION: Elevated levels of antibodies and certain cell subpopulations were observed in vaccinated adolescents, confirming the effectiveness of the BNT162b2 vaccine in maintaining humoral and cellular responses. This study is the first to describe data from indigenous minors vaccinated against COVID-19 with the BNT162b2 vaccine, highlighting the importance of vaccination efforts and the potential need for booster doses.

Trispecific anti-CD3/BCMA/CD38 antibodies for multiple myeloma: a patent evaluation of US20240132615.

INTRODUCTION: CD38 and BCMA are proteins expressed at high levels in multiple myeloma cells, so they are targets for the development of mono- or multispecific antibodies. AREAS COVERED: Patent US20240132615 describes anti-CD3/BCMA/CD38 trispecific antibodies and a method of treating relapsed/refractory multiple myeloma pharmaceutically. In vitro and preclinical results show that anti-CD3/BCMA/CD38 trispecific antibodies have stronger binding affinity and killing potency compared to daratumumab, isatuximab, and teclistamab antibodies. EXPERT OPINION: The trispecific structure and a silenced Fc are pharmaceutical advantages of the anti-CD3/BCMA/CD38 antibody for the treatment of relapsed or refractory multiple myeloma.

Safety and immunogenicity of a live-attenuated chikungunya virus vaccine in endemic areas of Brazil: interim results of a double-blind, randomised, placebo-controlled phase 3 trial in adolescents.

BACKGROUND: Chikungunya outbreaks have been reported in Brazil since 2014. Adolescents are a sensitive population who would benefit from a prophylactic vaccine. This study assessed the immunogenicity and safety of the vaccine VLA1553 in adolescents in Brazil. With an overall trial duration of 12 months, we now report data on safety and immunogenicity over a period of 28 days after vaccination. METHODS: In this double-blind, randomised, placebo-controlled phase 3 trial, adolescents aged 12 to <18 years were recruited. The trial was performed at ten trial sites across Brazil. Eligible participants were generally healthy. The main exclusion criteria comprised immune-mediated or chronic arthritis or arthralgia, a known or suspected defect of the immune system, or any live vaccine received within the 4 weeks before trial vaccination. Randomisation was stratified by baseline serostatus in a 2:1 ratio to receive VLA1553 (at a dose of 1 × 104 TCID50 per 0·5 mL [ie, 50% tissue culture infectious dose]) or placebo. VLA1553 or placebo was administered intramuscularly as a single-dose immunisation on day 1. The primary endpoint was the proportion of baseline seronegative participants with chikungunya virus neutralising antibody levels of 150 or more in µPRNT50 (a micro plaque reduction neutralisation test), which was considered a surrogate of protection. The safety analysis included all participants receiving a trial vaccination. Immunogenicity analyses were performed in a subset. The trial is registered with ClinicalTrials.gov, NCT04650399. FINDINGS: Between Feb 14, 2022, and March 14, 2023, 754 participants received a trial vaccination (502 received VLA1553 and 252 received placebo) with a per-protocol population of 351 participants for immunogenicity analyses (303 in the VLA1553 group and 48 in the placebo group). In participants who were seronegative at baseline, VLA1553 induced seroprotective chikungunya virus neutralising antibody levels in 247 of 250 (98·8%, 95% CI 96·5-99·8) participants 28 days after vaccination. In seropositive participants, the baseline seroprotection rate of 96·2% increased to 100% after vaccination with VLA1553. Most (365 [93%] of 393) adverse events were of mild or moderate intensity, VLA1553 was generally well tolerated. When compared with placebo, participants exposed to VLA1553 had a significantly higher frequency of related adverse events (351 [69·9%] of 502 vs 121 [48·0%] of 252; p<0·0001), mostly headache, myalgia, fatigue, and fever. Among four reported serious adverse events (three in the VLA1553 group and one in the placebo group), one was classified as possibly related to VLA1553: a high-grade fever. Among 20 adverse events of special interest (ie, symptoms suggesting chikungunya-like disease), 16 were classified as related to trial vaccination (15 in the VLA1553 group and one in the placebo group), with severe symptoms reported in four participants (fever, headache, or arthralgia). 17 adverse events of special interest resolved within 1 week. Among 85 participants with arthralgia (68 in the VLA1553 group and 17 in the placebo group), eight adolescents had short-lived (range 1-5 days), mostly mild recurring episodes (seven in the VLA1553 group and one in the placebo group). The median duration of arthralgia was 1 day (range 1-5 days). The frequency of injection site adverse events for VLA1553 was higher than in the placebo group (161 [32%] vs 62 [25%]), but rarely severe (two [<1%] in the VLA1553 group and one [<1%] in the placebo group). After administration of VLA1553, there was a significantly lower frequency of solicited adverse events in participants who were seropositive at baseline compared with those who were seronegative (53% vs 74%; p<0·0001) including headache, fatigue, fever, and arthralgia. INTERPRETATION: VLA1553 was generally safe and induced seroprotective titres in almost all vaccinated adolescents with favourable safety data in adolescents who were seropositive at baseline. The data support the use of VLA1553 for the prevention of disease caused by the chikungunya virus among adolescents and in endemic areas. FUNDING: Coalition for Epidemic Preparedness Innovation and EU Horizon 2020. TRANSLATION: For the Portuguese translation of the abstract see Supplementary Materials section.

Somatic Symptoms Are Associated With Elevated Blood Pressure and Epstein-Barr Virus Antibodies Among Shuar of the Ecuadorian Amazon.

INTRODUCTION: This study tests the hypothesis that self-reported somatic symptoms are associated with biomarkers of stress, including elevated blood pressure and suppressed immune function, among Shuar adults living in the Ecuadorian Amazon. METHODS: Research was conducted in three Shuar communities in the Upano Valley of the Ecuadorian Amazon and included the collection of biomarkers and a structured morbidity interview. Participants self-reported somatic symptoms such as headaches, body pain, fatigue, and other bodily symptoms. We examined whether the number of somatic symptoms reported was associated with measures of immune (Epstein-Barr virus [EBV] antibodies) and cardiovascular (blood pressure) functioning in 97 Shuar adults (37 women, 60 men; ages 18-65 years). Multivariate linear regression analyses were used to examine the relationships among somatic symptoms and stress biomarkers, controlling for age, sex, body mass index (BMI), active infection, level of education, and income. RESULTS: Controlling for relevant covariates, Shuar adults reporting the highest level of somatic symptoms (three symptoms) were more likely to exhibit elevated systolic (ß = 0.20, p = 0.04) and diastolic blood pressure (ß = 0.23, p = 0.03), in comparison to adults reporting no symptoms. Shuar adults reporting two symptoms, compared to no symptoms, were more likely to exhibit elevated EBV antibody concentrations (ß = 0.34, p = < 0.01). CONCLUSIONS: These preliminary findings demonstrate that somatic symptoms reported by Shuar men and women are associated with physiological measures widely associated with chronic psychosocial stress. These findings complement the cross-cultural literature in medical anthropology documenting the close connection between the expression of somatic symptoms and stressful life circumstances and highlight the important role that human biologists can play in exploring biocultural phenomena.

Rescuing pathogen-specific memory B-cell from PBMC of prior Zika virus-infected individuals.

Immunological memory, a fundamental immune system mechanism, is instrumental in long-term protection. Successful vaccines can elicit and sustain immunological memory against pathogens for the long term. Memory B cells (MBC) are key players in secondary responses due to their longevity and rapid differentiation into high-affinity antibody-secreting cells upon second antigen exposure. However, the availability of circulating MBCs is limited. Here we describe a protocol, which presents a straightforward and practical method for activating and expanding Zika virus (ZIKV) specific MBC. PBMCs collected from individuals who had been infected with ZIKV two years prior were cultured by supplementing with IL-2 and R848, a TLR-7/8 agonist, and then pulsed with inactivated virus. After seven days, this stimulation led to a notable rise in virus-specific functional MBC, as evidenced by a significant increase in the production of anti-ZIKV IgG. Importantly, the ZIKV pulse did not induce changes in the PBMC culture of individuals without a history of ZIKV infection. These findings demonstrate that virus-specific MBC can be expanded in vitro, even using PBMC cultures from individuals infected years before. Therefore, our protocol is a practical and effective tool for studies that require a larger number of human MBCs from previously infected individuals that are functional and specific to the pathogen under investigation.