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In Brazil, at least four lineages of influenza A virus circulate pig population: 2009 H1N1 flu pandemic (pH1N1), human-seasonal origin H3N2, H1N1 and H1N2 (huH1 lineages) viruses. Studies related to the occurrence of swine influenza A virus (SIAV) in Brazilian herds have been detecting an increase of occurrence of huH1 lineages. This study aimed to construct recombinant vaccines against the huH1N1 virus and test the immunogens in a murine model. The virus was constructed by reverse genetics using plasmids encoding the HA and NA sequences from a wild huH1N1 virus isolated from an infected pig. Amplified virus was inactivated, and oil-in-water (OW) and gel polymer (GP) adjuvants were used to formulate the vaccines. C57Bl6 mice received two doses with 3 weeks interval by the intramuscular route. Animals were randomly divided into 8 groups (G1-G8): G1 received OW vaccine and G2 PBS plus OW adjuvant; G3 received GP vaccine and G4 PBS plus GP adjuvant; G5 received the live virus by the intranasal route while G6 only PBS; G7 and G8 did not receive any treatment. Serum samples were collected before vaccination and after the first and second dose. Except for G8, three weeks post boost animals were challenged with a wild huH1N1 virus and observed for weight changes. After infection, bronchoalveolar lavage fluid (BALF) and lungs were collected from animals of each group for viral titers and immunohistochemistry (IHC) analysis, respectively. After booster, vaccinated groups seroconverted and the vaccines induced protection upon challenge. Reverse Genetics technique can be used to produce new and quickly updated swine influenza vaccines which is promising to control the virus in Brazilian herds. Future studies may focus on using the technology to produce multivalent recombinant vaccines against distinct strains of SIAVs circulating in Brazilian pig herds. •At least four lineages of swine influenza virus circulate in Brazilian pig herds.•The circulation of different strains poses challenges to control the disease in the country.•Searching for different vaccination methods with efficient adjuvants is crucial for swine influenza control.•The reverse genetics' technique constitutes an important alternative platform for obtaining safe and effective vaccines.

Introduction Zika virus (ZIKV) caused an outbreak in Brazil, in 2015, being associated to microcephaly. ZIKV has a strong neurotropism leading to death of infected cells in different brain regions, including the hippocampus, a major site for neurogenesis. The neuronal populations of the brain are affected differently by ZIKV from Asian and African ancestral lineages. However, it remains to be investigated whether subtle variations in the ZIKV genome can impact hippocampus infection dynamics and host response. Objective This study evaluated how two Brazilian ZIKV isolates, PE243 and SPH2015, that differ in two specific missense amino acid substitutions, one in the NS1 protein and the other in the NS4A protein, affect the hippocampal phenotype and transcriptome. Methods Organotypic hippocampal cultures (OHC) from infant Wistar rats were infected with PE243 or SPH2015 and analyzed in time series using immunofluorescence, confocal microscopy, RNA-Seq and RT-qPCR. Results Unique patterns of infection and changes in neuronal density in the OHC were observed for PE243 and SPH2015 between 8 and 48 h post infection (p.i.). Phenotypic analysis of microglia indicated that SPH2015 has a greater capacity for immune evasion. Transcriptome analysis of OHC at 16 h p.i. disclosed 32 and 113 differentially expressed genes (DEGs) in response to infection with PE243 and SPH2015, respectively. Functional enrichment analysis suggested that infection with SPH2015 activates mostly astrocytes rather than microglia. PE243 downregulated biological process of proliferation of brain cells and upregulated those associated with neuron death, while SPH2015 downregulated processes related to neuronal development. Both isolates downregulated cognitive and behavioral development processes. Ten genes were similarly regulated by both isolates. They are putative biomarkers of early hippocampus response to ZIKV infection. At 5, 7, and 10 days p.i., neuronal density of infected OHC remained below controls, and mature neurons of infected OHC showed an increase in the epigenetic mark H3K4me3, which is associated to a transcriptionally active state. This feature is more prominent in response to SPH2015. Conclusion Subtle genetic diversity of the ZIKV affects the dynamics of viral dissemination in the hippocampus and host response in the early stages of infection, which may lead to different long-term effects in neuronal population.

The swine influenza A virus (SIAV) subtypes/lineages H1N1pdm09, H3N2, H1N2, and H1N1 of seasonal human origin are widespread in Brazilian swine herds. A monovalent inactivated H1N1pdm09 vaccine was licensed in Brazil in 2014. However, there are concerns about its efficacy due to the limited vaccine cross-protection against heterologous viruses and the potential for exacerbated reactions against vaccine strains. Thus, monitoring SIAVs subtypes/lineages that are circulating in the Brazilian swine population is important, by applying a fast and efficient diagnostic test in herd field samples. A RT-PCR assay was developed, using primers specific for HA subtyping of Brazilian SIAV, and was used to evaluate the occurrence of subtypes from samples collected between 2012 and 2019. From 167 field samples positive for influenza A, 117 were subtyped by nested RT-PCR assay. A higher occurrence of H1N1pdm was observed from 2012 to 2015, H3N2 in 2017, and H1hu in 2017 to 2019. A hemagglutination inhibition test was performed in serum samples received from 2017 to 2019, confirming these data. The molecular data highlights the importance of H1hu and H3N2 detection since there are no vaccines available for the subtypes/lineages and raises an alert of H1hu for its potential to infect humans. Serological data suggest a cyclical profile of occurrence between the H3N2 and H1N1pdm over time. Monitoring SIAVs circulating in Brazilian swine herds is necessary, which provides the relevant information for field veterinarians to apply effective control measures on the properties.

Streptococcus pneumoniae and influenza A virus (IAV) are significant agents of pneumonia cases and severe respiratory infections globally. Secondary bacterial infections, particularly by Streptococcus pneumoniae , are common in IAV-infected individuals, leading to critical outcomes. Despite reducing mortality, pneumococcal vaccines have high production costs and are serotype specific. The emergence of new circulating serotypes has led to the search for new prevention strategies that provide a broad spectrum of protection. In this context, vaccination using antigens present in all serotypes, such as Pneumococcal Surface Protein A (PspA), can offer broad coverage regardless of serotype. Employing the reverse genetics technique, our research group developed a recombinant influenza A H1N1 virus that expresses PspA (Flu-PspA), through the replacement of neuraminidase by PspA. This virus was evaluated as a bivalent vaccine against infections caused by influenza A and S. pneumoniae in mice. Initially, we evaluated the Flu-PspA virus’s ability to infect cells and express PspA in vitro, its capacity to multiply in embryonated chicken eggs, and its safety when inoculated in mice. Subsequently, the protective effect against influenza A and Streptococcus pneumoniae lethal challenge infections in mice was assessed using different immunization protocols. Analysis of the production of antibodies against PspA4 protein and influenza, and the binding capacity of anti-PspA4 antibodies/complement deposition to different strains of S. pneumoniae were also evaluated. Our results demonstrate that the Flu-PspA virus vaccine efficiently induces PspA protein expression in vitro, and that it was able to multiply in embryonated chicken eggs even without exogenous neuraminidase. The Flu-PspA-based bivalent vaccine was demonstrated to be safe, stimulated high titers of anti-PspA and anti-influenza antibodies, and protected mice against homosubtypic and heterosubtypic influenza A and S. pneumoniae challenge. Moreover, an efficient binding of antibodies and complement deposition on the surface of pneumococcal strains ascribes the broad-spectrum vaccine response in vivo. In summary, this innovative approach holds promise for developing a dual-protective vaccine against two major respiratory pathogens.

Recombinant influenza viruses are promising viral platforms to be used as antigen delivery vectors. To this aim, one of the most promising approaches consists of generating recombinant viruses harboring partially truncated neuraminidase (NA) segments. To date, all studies have pointed to safety and usefulness of this viral platform. However, some aspects of the inflammatory and immune responses triggered by those recombinant viruses and their safety to immunocompromised hosts remained to be elucidated. In the present study, we generated a recombinant influenza virus harboring a truncated NA segment (vNA-Δ) and evaluated the innate and inflammatory responses and the safety of this recombinant virus in wild type or knock-out (KO) mice with impaired innate (Myd88 -/-) or acquired (RAG -/-) immune responses. Infection using truncated neuraminidase influenza virus was harmless regarding lung and systemic inflammatory response in wild type mice and was highly attenuated in KO mice. We also demonstrated that vNA-Δ infection does not induce unbalanced cytokine production that strongly contributes to lung damage in infected mice. In addition, the recombinant influenza virus was able to trigger both local and systemic virus-specific humoral and CD8+ T cellular immune responses which protected immunized mice against the challenge with a lethal dose of homologous A/PR8/34 influenza virus. Taken together, our findings suggest and reinforce the safety of using NA deleted influenza viruses as antigen delivery vectors against human or veterinary pathogens.

Background: To prospectively evaluate the safety and clinical impact of SARS-CoV-2 vaccines in patients with systemic lupus erythematosus (SLE). Methods: Subanalysis of the Brazilian multicenter observational study “Safety, Effectiveness and Duration of Immunity after Vaccination against SARS-CoV-2 in Patients with Immune-Mediated Inflammatory Diseases (SAFER)”, which included SLE patients vaccinated with CoronaVac, ChAdOx1, or BNT162b2. Patients with HIV infection, pregnant women, or those with immunosuppression not related to SLE were excluded. Safety data related to adverse events and underlying disease activity were assessed. Additionally, COVID-19 cases were monitored throughout the follow-up period. Results: The study included 373 patients with systemic lupus erythematosus (SLE), with a mean age of 36 years, the majority being women (89.8%). The most common adverse events after SARS-CoV-2 vaccination were injection site reactions and headache, observed both after the first and subsequent doses. The ChAdOx-1 vaccine was associated with a higher frequency of adverse events compared to CoronaVac. At baseline, 38.3% of patients were in remission, 32.8% had low disease activity, and 28.9% had moderate to high activity. Following CoronaVac vaccination, there was an increase in remission rates (from 34.6% to 51.1%) and a significant reduction in moderate to high activity (from 37.6% to 15.0%) after the first dose, with this reduction partially maintained after the second dose. In contrast, patients vaccinated with ChAdOx-1 showed an increase in moderate to high activity (from 14.5% to 38.2% after the first dose), a trend that persisted after the second dose. No statistically significant changes in disease activity were observed among those who received BNT162b2. During follow-up, 44 cases of COVID-19 were reported, all mild, with no deaths or need for intensive care unit admission. Conclusions: Vaccination against SARS-CoV-2 demonstrated a favorable safety profile in patients with SLE, with a low frequency of serious adverse events. While analysis of disease activity revealed variations across vaccine platforms, most notably an increased proportion of moderate to high disease activity among those receiving ChAdOx-1 compared with CoronaVac and BNT162b2, the overall occurrence of COVID-19 during follow-up was limited to mild cases, with no severe outcomes. These findings highlight that, despite potential risks of disease exacerbation, the clear protection against severe COVID-19 supports vaccination as a beneficial strategy for this immunocompromised population.

In Brazil, data show an important decrease in morbi-mortality of high-risk surgical patients over a 10-year high. The objective of this post-hoc study was to evaluate the mechanism explaining this trend in high-risk surgical patients admitted to Brazilian ICUs in two large Brazilian multicenter cohort studies performed 10 years apart. The patients included in the 2 cohorts studies published in 2008 and 2018 were compared after a (1:1) propensity score matching. Patients included were adults who underwent surgeries and admitted to the ICU afterwards. After matching, 704 patients were analyzed. Compared to the 2018 cohort, 2008 cohort had more postoperative infections (OR 13.4; 95%CI 6.1-29.3) and cardiovascular complications (OR 1.5; 95%CI 1.0-2.2), as well as a lower survival ICU stay (HR = 2.39, 95% CI: 1.36-4.20) and hospital stay (HR = 1.64, 95% CI: 1.03-2.62). In addition, by verifying factors strongly associated with hospital mortality, it was found that the risk of death correlated with higher intraoperative fluid balance (OR = 1.03, 95% CI 1.01-1.06), higher creatinine (OR = 1.31, 95% CI 1.1-1.56), and intraoperative blood transfusion (OR = 2.32, 95% CI 1.35-4.0). By increasing the mean arterial pressure, according to the limits of sample values from 43 mmHg to 118 mmHg, the risk of death decreased (OR = 0.97, 95% CI 0.95-0.98). The 2008 cohort had higher fluid balance, postoperative creatinine, and volume of intraoperative blood transfused and lower mean blood pressure at ICU admission and temperature at the end of surgery. In this sample of ICUs in Brazil, high-risk surgical patients still have a high rate of complications, but with improvement over a period of 10 years. There were changes in the management of these patients over time.

Objective: To evaluate the humoral response to and impact of SARS-CoV-2 vaccination in patients with systemic lupus erythematosus in a multicenter cohort design. Methods: Data for this analysis were obtained from the Study of Safety, Effectiveness and Duration of Immunity after Vaccination against SARS-CoV-2 in Patients with Immune-Mediated Inflammatory Diseases (SAFER), a prospective, multicenter, phase IV, real-world study conducted across different regions of Brazil from June/2021 to March/2024. Patients aged >18 years with systemic lupus erythematosus (SLE) who received any one of the SARS-CoV-2 vaccines approved by the Brazilian health regulatory agency (CoronaVac [inactivated SARS-CoV-2 vaccine], ChAdOx-1 [AstraZeneca], or BNT162b2 [Pfizer-BioNTech]) were included. Immunogenicity was assessed in pre- and post-vaccination blood samples, and patients were monitored in person and remotely for the occurrence and severity of COVID-19. Results: Two hundred and thirty-five patients with SLE who had completed their vaccination schedules (two doses + booster dose) were included in this study. Most patients were female (89.3%) and had low disease activity or were in remission (72.4%); the majority were also on some form of immunosuppressive therapy (58.1%). One hundred and sixteen patients received two doses of CoronaVac followed by one dose of BNT162b2 (Pfizer-BioNTech) vaccine, eighty-seven received two doses of ChAdOx1-S (AstraZeneca) followed by one dose of BNT162b2 (Pfizer-BioNTech) vaccine, and thirty-two received three doses of BNT162b2 (Pfizer-BioNTech) vaccine. Twenty-eight cases of COVID-19, none meeting criteria for severe COVID-19, were recorded in patients with respiratory symptoms after the second dose of a SARS-CoV-2 vaccine. Regarding immunogenicity, an increase in seroconversion rate was observed following consecutive vaccine doses, with no difference between vaccination schedules, reaching 97.57% seropositivity after a booster dose. The geometric mean IgG titers differed between the different vaccination schedules after the first and the second vaccine dose, being lowest for the CoronaVac-based schedule, but titers were similar after the administration of a booster dose. Conclusion: In patients with SLE, SARS-CoV-2 vaccines are immunogenic, inducing a robust humoral response. No severe outcomes associated with death or hospitalization were found in the evaluated patient sample. Complete vaccination schedules including a booster dose induced higher humoral responses than incomplete schedules, especially in patients initially immunized with an inactivated virus vaccine schedule and those with a suboptimal humoral response.

BackgroundThe immune response and safety using different COVID-19 vaccine platforms in patients with immune mediated rheumatic diseases is still uncertain. The objective of this study is to compare the immunogenicity and safety after two doses of BNT162b2, CoronaVac and ChadOx-1 in SLE patients.MethodsProspective study including SLE patients who received a primary schedule to COVID-19 vaccination between May and August 2021. Immunogenicity, events supposedly attributable to vaccination or immunization (ESAVI) and disease activity were assessed at baseline and after each vaccine dose.Results121 SLE patients were included in the cohort, 88 in the immunogenicity analysis and 118 in the safety analysis. The groups were homogenous concerning sex, age, and comorbidities. Seropositivity after two doses of vaccines was similar between CoronaVac (68%), ChadOx1 (80,6%) and BNT162b2 (88%) (p=0.231). However, CoronaVac and ChadOx-1 presented lower titers in comparison with BNT162b2. Regarding ESAVI, the most frequent reported following first and second vaccine doses were, respectively: injection site pain (65.2%/41.1%), headache (50.9%/29.9%) and arthralgia (37.5%/22.5%). Fever and myalgia were more related to ChAdOx1 than CoronaVac (23.3 vs. 5.0%; p=0.025). There was no difference in MEX-SLEDAI between vaccine platforms. No serious ESAVI were reported.ConclusionAfter two doses, the three COVID-19 vaccine platforms induced a significant increase in antibody titers against SARS-CoV-2. Patients who received BNT162b2 exhibited a higher serological response compared to the other vaccines. All three vaccine platforms demonstrated a favorable safety profile, with no serious ESAVI or worsening of disease activity.Clinical trial NumberThe study was registered in The Brazilian Registry of Clinical Trials (ReBEC) in 04/14/2021 with code RBR-108fyykd.

Patients with systemic vasculitis faced the risk of severe COVID-19 and high mortality during the pandemic. Although SARS-CoV-2 vaccination mitigates these outcomes, vaccine hesitancy persists, and data on immunogenicity and safety in vasculitis is still limited. This study aims to assess response to primary and booster doses of SARS-CoV-2 vaccination in systemic vasculitis. This multicenter cohort study including systemic vasculitis included patients from SAFER study (Safety and Efficacy of COVID-19 Vaccines in Rheumatic Diseases). We evaluated serum IgG levels against the SARS-CoV-2 spike protein receptor-binding domain (IgG anti-RBD) at baseline and 28 days post-vaccination, disease activity scores, new cases of COVID-19 infections, and adverse events. Seventy-three patients with systemic vasculitis were included. Behçet's disease (n=39), Takayasu arteritis (n=15), and antineutrophil cytoplasmic antibody-associated vasculitis (n=14) were the most common vasculitis forms. The majority of the patients had no comorbidities and were in remission. Seventy patients received one, 65 two, and 60 three vaccine doses. ChAdOx1 nCoV-19 (AstraZeneca/Oxford) (n=36) and CoronaVac (Sinovac) (n=25) were primarily the most common vaccines, while BNT162b2 (Pfizer-BioNTech) was usually the booster vaccine. ChAdOx1 nCoV-19 induced higher IgG anti-RBD than CoronaVac after two doses ( =0.002), but this difference disappeared after the booster dose. No differences in vaccine response were noted between heterologous and homologous regimens or vasculitis types. The new cases of COVID-19 (16.9%), hospitalization (1.5%), and mortality (1.5%) rates were relatively low following vaccination. Disease activity remained stable, and adverse events were mostly mild. Only one severe adverse event was observed. Different SARS-CoV-2 vaccines demonstrated immunogenicity and clinical effectiveness in systemic vasculitis. The three-dose schedule was safe without increasing relapse risk.