Virus-like particle-based multipathogen vaccine of FMD and SVA elicits balanced and broad protective efficacy in mice and pigs.

Inactivated vaccines lack the capability to serologically differentiate between infected and vaccinated animals, thereby impeding the effective eradication of pathogen. Conversely, vaccines based on virus-like particles (VLPs) emulate natural viruses in both size and antigenic structure, presenting a promising alternative to overcome these limitations. As the complexity of swine infectious diseases increases, the increase of vaccine types and doses may intensify the stress response. This exacerbation can lead to diminished productivity, failure of immunization, and elevated costs. Given the critical dynamics of co-infection and the clinically indistinguishable symptoms associated with foot-and-mouth disease virus (FMDV) and senecavirus A (SVA), there is a dire need for an efficacious intervention. To address these challenges, we developed a combined vaccine composed of three distinct VLPs, specifically designed to target SVA and FMDV serotypes O and A. Our research demonstrates that this trivalent VLP vaccine induces antigen-specific and robust serum antibody responses, comparable to those produced by the respective monovalent vaccines. Moreover, the immune sera from the combined VLP vaccine strongly neutralized FMDV type A and O, and SVA, with neutralization titers comparable to those of the individual vaccines, indicating a high level of immunogenic compatibility among the three VLP components. Importantly, the combined VLPs vaccines-immunized sera conferred efficient protection against single or mixed infections with FMDV type A and O, and SVA viruses in pigs. In contrast, individual vaccines could only protect pigs against homologous virus infections and not against heterologous challenges. This study presents a novel combined vaccines candidate against FMD and SVA, and provides new insights for the development of combination vaccines for other viral swine diseases.

Intranasal booster vaccination of beef steers reduces clinical signs following experimental coinfection with BRSV and BHV-1 without reducing shedding of BRD-associated bacteria.

OBJECTIVE: To determine the efficacy of primary or booster intranasal vaccination of beef steers on clinical protection and pathogen detection following simultaneous challenge with bovine respiratory syncytial virus and bovine herpes virus 1. METHODS: 30 beef steers were randomly allocated to 3 different treatment groups starting at 2 months of age. Group A (n = 10) was administered a single dose of a parenteral modified-live vaccine and was moved to a separate pasture. Groups B (n = 10) and C (10) remained unvaccinated. At 6 months of age, all steers were weaned and transported. Subsequently, groups A and B received a single dose of an intranasal modified-live vaccine vaccine while group C remained unvaccinated. Group C was housed separately until challenge. Two days following vaccination, all steers were challenged with bovine respiratory syncytial virus and bovine herpes virus 1 and housed in a single pen. Clinical and antibody response outcomes and the presence of nasal pathogens were evaluated. RESULTS: The odds of clinical disease were lower in group A compared with group C on day 7 postchallenge; however, antibody responses and pathogen detection were not significantly different between groups before and following viral challenge. All calves remained negative for Histophilus somni and Mycoplasma bovis; however, significantly greater loads of Mannheimia haemolytica and Pasteurella multocida were detected on day 7 postchallenge compared with day -2 prechallenge. CLINICAL RELEVANCE: Intranasal booster vaccination of beef steers at 6 months of age reduced clinical disease early after viral challenge. Weaning, transport, and viral infection promoted increased detection rates of M haemolytica and P multocida regardless of vaccination status.

Prevention of Viral Hepatitis and HIV Infection among People Who Inject Drugs: A Systematic Review and Meta-Analysis.

This study aimed to explore the current evidence on preventing blood-borne virus infections among people who inject drugs (PWID). We conducted a comprehensive search across three databases (PubMed, Embase, Cochrane Library) for relevant articles published in English between 2014 and 2023. We followed the Preferred Reporting Items for Systematic Reviews and Meta Analysis (PRISMA) guidelines, assessed the quality of the paper using the revised Cochrane Risk of Bias Tool (ROB 2), and conducted a meta-analysis using RevMan 5.3. Completing the harm reduction program (HRP) participation and receiving all three vaccine doses resulted in a 28% reduction in the risk of HBV infection (OR: 0.72, 95% CI: 0.37-1.42). Various interventions increased the willingness of PWIDs to undergo HCV treatment (OR: 5.91, 95% CI: 2.46-14.24) and promoted treatment adherence (OR: 15.04, 95% CI: 2.80-80.61). Taking PrEP, participating in HRP, and modifying risky behaviors were associated with a 33% reduction in the risk of HIV infection (OR: 0.67, 95% CI: 0.61-0.74). Conducting referrals, providing counseling, and implementing antiretroviral therapy resulted in a 44% reduction in the risk of viral transmission (OR: 0.56, 95% CI: 0.47-0.66). Co-infection may potentially compromise effectiveness, so it is important to consider drug resistance.

Hepatitis D: A Review.

Importance: Hepatitis D virus (HDV) infection occurs in association with hepatitis B virus (HBV) infection and affects approximately 12 million to 72 million people worldwide. HDV causes more rapid progression to cirrhosis and higher rates of hepatocellular carcinoma than HBV alone or hepatitis C virus. Observations: HDV requires HBV to enter hepatocytes and to assemble and secrete new virions. Acute HDV-HBV coinfection is followed by clearance of both viruses in approximately 95% of people, whereas HDV superinfection in an HBV-infected person results in chronic HDV-HBV infection in more than 90% of infected patients. Chronic hepatitis D causes more rapidly progressive liver disease than HBV alone. Approximately 30% to 70% of patients with chronic hepatitis D have cirrhosis at diagnosis and more than 50% die of liver disease within 10 years of diagnosis. However, recent studies suggested that progression is variable and that more than 50% of people may have an indolent course. Only approximately 20% to 50% of people infected by hepatitis D have been diagnosed due to lack of awareness and limited access to reliable diagnostic tests for the HDV antibody and HDV RNA. The HBV vaccine prevents HDV infection by preventing HBV infection, but no vaccines are available to protect those with established HBV infection against HDV. Interferon alfa inhibits HDV replication and reduces the incidence of liver-related events such as liver decompensation, hepatocellular carcinoma, liver transplant, or mortality from 8.5% per year to 3.3% per year. Adverse effects from interferon alfa such as fatigue, depression, and bone marrow suppression are common. HBV nucleos(t)ide analogues, such as entecavir or tenofovir, are ineffective against HDV. Phase 3 randomized clinical trials of bulevirtide, which blocks entry of HDV into hepatocytes, and lonafarnib, which interferes with HDV assembly, showed that compared with placebo or observation, these therapies attained virological and biochemical response in up to 56% of patients after 96 weeks of bulevirtide monotherapy and 19% after 48 weeks of lonafarnib, ritonavir, and pegylated interferon alfa treatment. Conclusions and Relevance: HDV infection affects approximately 12 million to 72 million people worldwide and is associated with more rapid progression to cirrhosis and liver failure and higher rates of hepatocellular carcinoma than infection with HBV alone. Bulevirtide was recently approved for HDV in Europe, whereas pegylated interferon alfa is the only treatment available in most countries.

rM2e-ΔPly protein immunization induces protection against influenza viruses and its co-infection with Streptococcus pneumoniae in mice.

Current seasonal influenza A virus (IAV) vaccines only protect against specific virus and require annual reconstitution to accommodate the viral mutations. A universal influenza vaccination that protects against all IAV strains is urgently needed. The influenza matrix protein 2 ectodomain (M2e) is a potential universal IAV vaccine candidate, but it has a low immunogenicity. ΔA146Ply was proved to be an effective protein adjuvant. Therefore, ΔA146Ply was used as an adjuvant of M2e in this study to evaluate its protective effect against IAV-related infection. Herein, a novel rM2e protein containing multiple M2e originated from different species of IAV was constructed and expressed in Escherichia coli (E. coli). Meanwhile, we also constructed and expressed the rM2e-ΔPly protein in E. coli. These proteins were administered intramuscularly to BALB/c mice. rM2e-ΔPly protein induces higher levels of humoral and cellular responses compared with their comprising protein mixture or rM2e alone. rM2e-ΔPly protein enhances the survival rate, reduces viral loads and inflammatory response in lung challenged with PR8. The serum induced by rM2e-ΔPly protein can protect against PR8 by passive immunity and cross-react with multiple M2e peptides derived from different IAV subtypes. After IAV and Streptococcus pneumoniae (S. pneumoniae) co-infection, rM2e-Ply protein can improve survival, lower viral and bacterial burdens, and diminish inflammatory response in the lungs. These results demonstrate that rM2e-ΔPly protein can significantly protect against influenza virus, IAV and S. pneumoniae co-infection, indicating that rM2e-ΔPly protein has the potential to become a universal influenza vaccine.

Systemic Homologous Neutralizing Antibodies Are Inadequate for the Evaluation of Vaccine Protective Efficacy against Coinfection by High Virulent PEDV and PRRSV.

G2 porcine epidemic diarrhea virus (G2 PEDV) and highly pathogenic porcine reproductive and respiratory syndrome virus 2 (HP-PRRSV2) are two of the most prevalent swine pathogens in China's swine herds, and their coinfection occurs commonly. Several PED and PRRS vaccines have been utilized in China for decades, and systemic homologous neutralizing antibodies (shnAbs) in serum are frequently used to evaluate the protective efficacy of PED and PRRS vaccines. To develop a vaccine candidate against G2 PEDV and HP-PRRSV2 coinfection, in this study, we generated a chimeric virus (rJSTZ1712-12-S) expressing S protein of G2 PEDV using an avirulent HP-PRRSV2 rJSTZ1712-12 infectious clone as the viral vector. The rJSTZ1712-12-S strain has similar replication efficacies as the parental rJSTZ1712-12 virus. In addition, animal inoculation indicated that rJSTZ1712-12-S is not pathogenic to piglets and can induce shnAbs against both G2 PEDV and HP-PRRSV2 isolates after prime-boost immunization. However, passive transfer study in neonatal piglets deprived of sow colostrum showed that rJSTZ1712-12-S-induced shnAbs may only decrease PEDV and PRRSV viremia but cannot confer sufficient protection against dual challenge of high virulent G2 PEDV XJ1904-34 strain and HP-PRRSV2 XJ17-5 isolate. Overall, this study provides the first evidence that shnAbs confer insufficient protection against PEDV and PRRSV coinfection and are inadequate for the evaluation of protective efficacy of PED and PRRS bivalent vaccine (especially for the PED vaccine). IMPORTANCE Porcine epidemic diarrhea virus (PEDV) and porcine reproductive and respiratory syndrome virus (PRRSV) coinfection occurs commonly and can synergistically reduce feed intake and pig growth. Vaccination is an effective strategy utilized for PED and PRRS control, and systemic homologous neutralizing antibodies (shnAbs) in serum are commonly used for protective efficacy evaluation of PED and PRRS vaccines. Currently, no commercial vaccine is available against PEDV and PRRSV coinfection. This study generated a chimeric vaccine candidate against the coinfection of prevalent PEDV and PRRSV in China. The chimeric strain can induce satisfied shnAbs against both PEDV and PRRSV after prime-boost inoculation in pigs. But the shnAbs cannot confer sufficient protection against PEDV and PRRSV coinfection in neonatal piglets. To the best of our knowledge, these findings provide the first evidence that shnAbs confer insufficient protection against PEDV and PRRSV coinfection and are inadequate for evaluating PED and PRRS bivalent vaccine protective efficacy.

Mathematical model analysis and numerical simulation for codynamics of meningitis and pneumonia infection with intervention.

In this paper, we have considered a deterministic mathematical model to analyze effective interventions for meningitis and pneumonia coinfection as well as to make a rational recommendation to public healthy, policy or decision makers and programs implementers. We have introduced the epidemiology of infectious diseases, the epidemiology of meningitis, the epidemiology of pneumonia, and the epidemiology of infection of meningitis and pneumonia. The positivity and boundedness of the sated model was shown. Our model elucidate that, the disease free equilibrium points of each model are locally asymptotically stable if the corresponding reproduction numbers are less than one and globally asymptotically stable if the corresponding reproduction numbers are greater than one. Additionally, we have analyzed the existence and uniqueness of the endemic equilibrium point of each sub models, local stability and global stability of the endemic equilibrium points for each model. By using standard values of parameters we have obtained from different studies, we found that the effective reproduction numbers of meningitis [Formula: see text] and effective reproduction numbers of pneumonia [Formula: see text] that lead us to the effective reproduction number of the meningitis and pneumonia co-infected model is [Formula: see text]. Applying sensitivity analysis, we identified the most influential parameters that can change the behavior of the solution of the meningitis pneumonia coinfection dynamical system are [Formula: see text] and [Formula: see text]. Biologically, decrease in [Formula: see text] and increasing in [Formula: see text] is a possible intervention strategy to reduce the infectious from communities. Finally, our numerical simulation has shown that vaccination against those diseases, reducing contact with infectious persons and treatment have the great effect on reduction of these silent killer diseases from the communities.

IFN-γ Attenuates Eosinophilic Inflammation but Is Not Essential for Protection against RSV-Enhanced Asthmatic Comorbidity in Adult Mice.

The susceptibility to respiratory syncytial virus (RSV) infection in early life has been associated with a deficient T-helper cell type 1 (Th1) response. Conversely, healthy adults generally do not exhibit severe illness from RSV infection. In the current study, we investigated whether Th1 cytokine IFN-γ is essential for protection against RSV and RSV-associated comorbidities in adult mice. We found that, distinct from influenza virus, prior RSV infection does not induce significant IFN-γ production and susceptibility to secondary Streptococcus pneumoniae infection in adult wild-type (WT) mice. In ovalbumin (OVA)-induced asthmatic mice, RSV super-infection increases airway neutrophil recruitment and inflammatory lung damage but has no significant effect on OVA-induced eosinophilia. Compared with WT controls, RSV infection of asthmatic Ifng-/- mice results in increased airway eosinophil accumulation. However, a comparable increase in eosinophilia was detected in house dust mite (HDM)-induced asthmatic Ifng-/- mice in the absence of RSV infection. Furthermore, neither WT nor Ifng-/- mice exhibit apparent eosinophil infiltration during RSV infection alone. Together, these findings indicate that, despite its critical role in limiting eosinophilic inflammation during asthma, IFN-γ is not essential for protection against RSV-induced exacerbation of asthmatic inflammation in adult mice.

SARS-CoV-2 and Influenza A Virus Coinfections in Ferrets.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and seasonal influenza viruses are cocirculating in the human population. However, only a few cases of viral coinfection with these two viruses have been documented in humans with some people having severe disease and others mild disease. To examine this phenomenon, ferrets were coinfected with SARS-CoV-2 and human seasonal influenza A viruses (IAVs; H1N1 or H3N2) and were compared to animals that received each virus alone. Ferrets were either immunologically naive to both viruses or vaccinated with the 2019 to 2020 split-inactivated influenza virus vaccine. Coinfected naive ferrets lost significantly more body weight than ferrets infected with each virus alone and had more severe inflammation in both the nose and lungs compared to that of ferrets that were single infected with each virus. Coinfected, naive animals had predominantly higher IAV titers than SARS-CoV-2 titers, and IAVs were efficiently transmitted by direct contact to the cohoused ferrets. Comparatively, SARS-CoV-2 failed to transmit to the ferrets that cohoused with coinfected ferrets by direct contact. Moreover, vaccination significantly reduced IAV titers and shortened the viral shedding but did not completely block direct contact transmission of the influenza virus. Notably, vaccination significantly ameliorated influenza-associated disease by protecting vaccinated animals from severe morbidity after IAV single infection or IAV and SARS-CoV-2 coinfection, suggesting that seasonal influenza virus vaccination is pivotal to prevent severe disease induced by IAV and SARS-CoV-2 coinfection during the COVID-19 pandemic. IMPORTANCE Influenza A viruses cause severe morbidity and mortality during each influenza virus season. The emergence of SARS-CoV-2 infection in the human population offers the opportunity to potential coinfections of both viruses. The development of useful animal models to assess the pathogenesis, transmission, and viral evolution of these viruses as they coinfect a host is of critical importance for the development of vaccines and therapeutics. The ability to prevent the most severe effects of viral coinfections can be studied using effect coinfection ferret models described in this report.

SARS-CoV-2 and HIV-1: Should HIV-1-Infected Individuals in Sub-Saharan Africa Be Considered a Priority Group for the COVID-19 Vaccines?

Since its emergence in 2019 SARS-CoV-2 has proven to have a higher level of morbidity and mortality compared to the other prevailing coronaviruses. Although initially most African countries were spared from the devastating effect of SARS-CoV-2, at present almost every country has been affected. Although no association has been established between being HIV-1-infected and being more vulnerable to contracting COVID-19, HIV-1-infected individuals have a greater risk of developing severe COVID-19 and of COVID-19 related mortality. The rapid development of the various types of COVID-19 vaccines has gone a long way in mitigating the devastating effects of the virus and has controlled its spread. However, global vaccine deployment has been uneven particularly in Africa. The emergence of SARS-CoV-2 variants, such as Beta and Delta, which seem to show some subtle resistance to the existing vaccines, suggests COVID-19 will still be a high-risk infection for years. In this review we report on the current impact of COVID-19 on HIV-1-infected individuals from an immunological perspective and attempt to make a case for prioritising COVID-19 vaccination for those living with HIV-1 in Sub-Saharan Africa (SSA) countries like Malawi as one way of minimising the impact of COVID-19 in these countries.

Low-dose tocilizumab is associated with improved outcome and a low risk of secondary infection in severe COVID-19 pneumonia.

BACKGROUND: Respiratory failure and death are the leading causes of severe Coronavirus disease 2019 (COVID-19). Hyper-inflammation and cytokine storm cause lung damage. This study aimed to compare the low-dose and high-dose effects of tocilizumab, an IL-6 receptor antagonist. METHOD: Patients with severe pneumonia and hyper-inflammation signs because of COVID-19 were included in this retrospective study. Patients receiving tocilizumab <200 mg intravenously were classified as the low-dose group, and receiving ≥200 mg as the high-dose group, and those not treated with tocilizumab as the control group. Demographic and clinical data of patients who died and survived in both low-high dose and control patients were compared. According to symptom day and radiological infiltration, patients with tocilizumab were also evaluated in two groups as early and late periods at tocilizumab administration time. RESULTS: A total of 160 patients were included in the study; 70 were treated with a low dose and 50 with high-dose tocilizumab. Forty patients were in the control group. Age, comorbidity and clinical features were similar in the control, low-dose tocilizumab and high-dose tocilizumab groups. The mortality rate (12.9%, 30.0%, 37.5, P = .008) was less in the low-dose tocilizumab group. The secondary infection rate was higher in the high-dose group than in the low-dose tocilizumab and control groups (44.0%, 10.0%, 10.0%, P < .001). Distinguishing between those patients who died and survived, age (OR: 1.1589, P < .001), higher APACHE II scores (OR: 1.225, P = .001) and needs for non-invasive mechanical ventilation (OR: 14.469, P < .001) were the most critical risk factors. Low-dose tocilizumab was associated with a lower mortality rate (OR: 0.244, P = .012). CONCLUSION: The use of tocilizumab at a low dose is associated with lower secondary infections and mortality.

Excreted Trypanosoma brucei proteins inhibit Plasmodium hepatic infection.

Malaria, a disease caused by Plasmodium parasites, remains a major threat to public health globally. It is the most common disease in patients with sleeping sickness, another parasitic illness, caused by Trypanosoma brucei. We have previously shown that a T. brucei infection impairs a secondary P. berghei liver infection and decreases malaria severity in mice. However, whether this effect requires an active trypanosome infection remained unknown. Here, we show that Plasmodium liver infection can also be inhibited by the serum of a mouse previously infected by T. brucei and by total protein lysates of this kinetoplastid. Biochemical characterisation showed that the anti-Plasmodium activity of the total T. brucei lysates depends on its protein fraction, but is independent of the abundant variant surface glycoprotein. Finally, we found that the protein(s) responsible for the inhibition of Plasmodium infection is/are present within a fraction of ~350 proteins that are excreted to the bloodstream of the host. We conclude that the defence mechanism developed by trypanosomes against Plasmodium relies on protein excretion. This study opens the door to the identification of novel antiplasmodial intervention strategies.

The Etiology of Pneumonia in HIV-1-infected South African Children in the Era of Antiretroviral Treatment: Findings From the Pneumonia Etiology Research for Child Health (PERCH) Study.

BACKGROUND: HIV-1 infection predisposes to an increased burden of pneumonia caused by community-acquired and opportunistic pathogens. METHODS: Within the context of the Pneumonia Etiology Research for Child Health case-control study of under 5 pneumonia, we investigated the etiology of World Health Organization-defined severe/very severe pneumonia requiring hospitalization in South African HIV-infected children. Nasopharyngeal-oropharyngeal swabs and blood, collected from cases and age- and season-matched HIV-infected controls attending outpatient antiretroviral therapy (ART) clinics, were analyzed using molecular diagnostic methods. Cases were also investigated for tuberculosis. Etiologic fractions among cases with radiologically confirmed pneumonia were derived using Bayesian analytic techniques. RESULTS: Of 115 HIV-infected cases, 89 (77.4%) had radiologically confirmed pneumonia. Severe immunosuppression (adjusted odds ratio, 32.60; 95% confidence interval, 7.25-146.64) was significantly associated with radiologically confirmed pneumonia. Cotrimoxazole prophylaxis (46.4% vs. 77.4%) and ART (28.2% vs. 83.1%) coverage were significantly lower in cases compared with ART-clinic controls. An etiologic agent was identified in 99.0% of the radiologically confirmed cases. The 'top 4' pathogens associated with radiologically confirmed pneumonia were Pneumocystis jirovecii [23.0%; 95% credible interval (CrI), 12.4%-31.5%], Staphylococcus aureus (10.6%; 95% CrI, 2.2%-20.2%), pneumococcus (9.5%; 95% CrI, 2.2%-18.0%) and respiratory syncytial virus (9.3%; 95% CrI, 2.2%-14.6%). Bacteremia (6.7%) and in-hospital death (10.1%) were frequent among those with radiologically confirmed disease. CONCLUSIONS: Pneumocystis jirovecii, S. aureus, pneumococcus and respiratory syncytial virus contribute a considerable burden of radiologically confirmed pneumonia in South African HIV-infected children under 5 years. Expediting access to ART and cotrimoxazole prophylaxis would decrease the burden of pneumonia in these children.

Discontinuation of Passive Immunization Is Safe after Liver Transplantation for Combined HBV/HDV Infection.

Patients after LT due to combined HBV/HDV infection are considered to be high-risk patients for recurrence of hepatitis B and D. To date, life-long prophylaxis with hepatitis B immunoglobulin (HBIG) and replication control with nucleos(t)ide analogs (NA) remains standard. We examined the course of 36 patients that underwent liver transplantation from 1989 to 2020 for combined HBV/HDV-associated end-stage liver disease in this retrospective study. Seventeen patients eventually discontinued HBIG therapy for various reasons. Their graft function, histopathological findings from routine liver biopsies and overall survival were compared with those that received an unaltered NA-based standard regimen combined with HBIG. The median follow-up was 204 and 227 months, respectively. The recurrence of HBV was 25% and did not differ between the groups of standard reinfection prophylaxis NA/HBIG (21.1%) and HBIG discontinuation (29.4%); (p = 0.56). No significant differences were found regarding the clinical course or histopathological aspects of liver tissue damage (inflammation, fibrosis, steatosis) between these two groups. Overall, and adjusted survival did not differ between the groups. Discontinuation of HBIG in stable patients after LT for combined HBV/HDV did not lead to impaired overall survival or higher recurrence rate of HBV/HDV infection in this long-term follow-up. Therefore, the recommendation of the duration of HBG administration must be questioned. The earliest time of discontinuation remains unclear.

COVID-19 Pandemic and Influenza Season in Hospitalized Patients: Concerns and Suggestions.

This is a letter to the editor.

Effects of schistosomes on host anti-viral immune response and the acquisition, virulence, and prevention of viral infections: A systematic review.

Although a growing number of studies suggest interactions between Schistosoma parasites and viral infections, the effects of schistosome infections on the host response to viruses have not been evaluated comprehensively. In this systematic review, we investigated how schistosomes impact incidence, virulence, and prevention of viral infections in humans and animals. We also evaluated immune effects of schistosomes in those coinfected with viruses. We screened 4,730 studies and included 103. Schistosomes may increase susceptibility to some viruses, including HIV and Kaposi's sarcoma-associated herpesvirus, and virulence of hepatitis B and C viruses. In contrast, schistosome infection may be protective in chronic HIV, Human T-cell Lymphotropic Virus-Type 1, and respiratory viruses, though further research is needed. Schistosome infections were consistently reported to impair immune responses to hepatitis B and possibly measles vaccines. Understanding the interplay between schistosomes and viruses has ramifications for anti-viral vaccination strategies and global control of viral infections.

Protective efficacy of mucosal and subcutaneous immunization with DnaJ-ΔA146Ply against influenza and Streptococcus pneumoniae co-infection in mice.

Respiratory tract coinfections, specifically involving influenza A virus (IAV) and Streptococcus pneumoniae (S. pneumoniae), remain a major health problem worldwide. Secondary bacterial pneumonia is a common complication and an important cause of mortality related to seasonal and pandemic influenza infections. Vaccination is a basic control strategy against influenza and S. pneumoniae. The fusion protein DnaJ-ΔA146Ply is a vaccine candidate which can induce immune responses against pneumococcal infections via mucosal and subcutaneous immunization in mice. In the present study, we established a co-infection model using mouse-adapted laboratory strains of IAV (PR8) and S. pneumoniae (19F) in mice intranasally and subcutaneously immunized with DnaJ-ΔA146Ply. Our results showed that vaccinated mice suffered decreased weight loss compared with control mice. The survival rates were higher in intranasally and subcutaneously immunized mice than in control mice. In addition, the bacterial loads in nasal washes and lung homogenates were lower in vaccinated mice than in control mice. Furthermore, lung damage was alleviated in vaccinated mice compared with control mice, with less broken alveoli and less proinflammatory cytokine production. Taken together, these results indicate that vaccination with DnaJ-ΔA146Ply shows protective potential against influenza and S. pneumoniae co-infection in mice.

Different incidences of acute kidney injury (AKI) and outcomes in COVID-19 patients with and without non-azithromycin antibiotics: A retrospective study.

In late December 2019, an outbreak of a novel coronavirus which caused coronavirus disease 2019 (COVID-19) was initiated. Acute kidney injury (AKI) was associated with higher severity and mortality of COVID-19. We aimed to evaluate the effects of comorbidities and medications in addition to determining the association between AKI, antibiotics against coinfections (AAC) and outcomes of patients. We conducted a retrospective study on adult patients hospitalized with COVID-19 in a tertiary center. Our primary outcomes were the incidence rate of AKI based on comorbidities and medications. The secondary outcome was to determine mortality, intensive care unit (ICU) admission, and prolonged hospitalization by AKI and AAC. Univariable and multivariable logistic regression method was used to explore predictive effects of AKI and AAC on outcomes. Out of 854 included participants, 118 patients developed AKI in whom, 57 used AAC and 61 did not. Hypertension and diabetes were the most common comorbidities in patients developed AKI. AAC, lopinavir/ritonavir, ribavirin, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers, and corticosteroids had significant higher rate of administration in patients developed AKI. AAC were associated with higher deaths (odds ratio [OR] = 5.13; 95% confidence interval (CI): 3-8.78) and ICU admission (OR = 5.87; 95%CI: 2.81-12.27), while AKI had higher OR for prolonged hospitalization (3.37; 95%CI: 1.76-6.45). Both AKI and AAC are associated with poor prognosis of COVID-19. Defining strict criteria regarding indications and types of antibiotics would help overcoming concomitant infections and minimizing related adverse events.

Zika virus infection during pregnancy protects against secondary infection in the absence of CD8+ cells.

While T cell immunity is an important component of the immune response to Zika virus (ZIKV) infection generally, the efficacy of these responses during pregnancy remains unknown. Here, we tested the capacity of CD8 lymphocytes to protect from secondary challenge in four macaques, two of which were depleted of CD8+ cells prior to rechallenge with a heterologous ZIKV isolate. The initial challenge during pregnancy produced transcriptional signatures suggesting complex patterns of immune modulation as well as neutralizing antibodies that persisted until rechallenge, which all animals efficiently controlled, demonstrating that the primary infection conferred adequate protection. The secondary challenge promoted activation of innate and adaptive immune cells, possibly suggesting a brief period of infection prior to clearance. These data confirm that ZIKV infection during pregnancy induces sufficient immunity to protect from a secondary challenge and suggest that this protection is not dependent on CD8 T cells.