Formalin-inactivated Vaccine Research Articles

A Combination of Chemotherapy and Autogenous Vaccine for Control of Bovine Papillomatosis in Cattle

The present study was conducted during the period from July, 2023 to January, 2024. Two clinical cases of cattle were reported with cutaneous papillomas, one near right umbilical region and another over the right hind teat of cattle. Both the animals were treated with a protocol designed such that it can regulate the secondary bacterial infection, speedy recovery of integument system and enhance the immune response for complete regression of the warts. The innate immune responses of infected animals were augmented with inactivated pathogen associated molecular patterns (PAMPs) as autogenous vaccine candidate. The warts were surgically excised, triturated in sterile PBS, inactivated with 0.5% formaline and prepared the autogenous vaccine. The sterility test of vaccine revealed that the vaccine was free from bacterial and fungal contaminants. The chemotherapy includes the use of drugs Thuja ointment, Inj.Enrofloxacin, Inj.Avil and Inj.Anthiomaline. The dose of the vaccine was 1 ml 20 kg-1 b.wt. subcutaneously and given at weekly intervals for a period of 4 weeks. It was observed that the treatment protocol was successfully effective and regression of warts was noticed from 2nd week onwards. By end of 4th week a complete recovery of the wart infected area was noticed with a black scar left behind. The formalin inactivated autogenous vaccine was effective, and applied for control of bovine papillomavirus infection in cattle with combination of chemotherapeutic drugs resulted in early regression of warts.

Comparative Studies of Nairobi-Sheep-Disease Virus Strains Infectivity, Immunogenicty and Cross- Protectivity in BALB/C Mice Model

Nairobi sheep disease virus is a hemorrhagic virus that cause severe gastroenteritis in shoats resulting to significant morbidity and mortality in naïve small ruminants’ populations. Vaccine platform to develop efficacious vaccine against the Nairobi sheep disease virus have been unsuccessful. This research detail the comparative infection, immunogenicity, and protection of three Nairobi sheep strains; I34, 1473 and Ansell. The three strains are marked with differences in their ability to cause disease in suckling mice model. Fatality rates range from 0-50% from the virulent pathogenic 1473 strain, I34 and the seemingly less virulent Ansell strain also shown by their relative time to death. Findings of this research demonstrate that protective efficacy mediated by inactivated Nairobi sheep disease virus strain I34 conferred a stronger cross protection against homologous and heterologous strains compared to 1473 and Ansell strains. Strain I34 sera neutralization against homologous I34 strain was similar to that against Entebe strain providing evidence of possible antigenic homology. Vaccine developed from I34 strain will protect against multiple strains of Nairobi sheep disease virus; 1473, Ansell and Entebe strain. Understanding immune response in mice elicited by different Nairobi sheep disease virus strains will facilitate development of a more efficacious vaccine. Using formalin inactivated NSDV vaccine, I34 strain showed complete protection from homologous and a partial protection heterologous strains in in vitro assay. Protection was associated by higher neutralizing antibodies against homologous and heterologous strains compared to that of 1473 and Ansell. Thus, this study deduce serum neutralizing antibody titers are associated with protection against homologous and heterologous challenge

Comparison of structure and immunogenicity of CVB1-VLP and inactivated CVB1 vaccine candidates.

Coxsackievirus B1 (CVB1) is a common cause of acute and chronic myocarditis, dilated cardiomyopathy and aseptic meningitis. However, no CVB-vaccines are available for human use. In this study, we investigated the immunogenicity of virus-like particle (VLP) and inactivated whole-virus vaccines for CVB1 when administrated to mice via either subcutaneous or intranasal routes formulated with and without commercial and experimental adjuvants. Here, the potential of utilizing epigallocatechin-3-gallate (EGCG) as a mucosal adjuvant synergistically with its ability to inactivate the virus were investigated. EGCG had promising adjuvant properties for CVB1-VLP when administered via the parenteral route but limited efficacy via intranasal administration. However, intranasal administration of the formalin-inactivated virus induced high CVB1-specific humoral, cellular, and mucosal immune responses. Also, based on CVB1-specific IgG-antibody responses, we conclude that CVB1-VLP can be taken up by immune cells when administrated intranasally and further structural engineering for the VLP may increase the mucosal immunogenicity. The preparations contained mixtures of compact and expanded A particles with 85% expanded in the formalin-inactivated virus, but only 52% in the VLP observed by cryogenic electron microscopy. To correlate the structure to immunogenicity, we solved the structures of the CVB1-VLP and the formalin-inactivated CVB1 virus at resolutions ranging from 2.15 A to 4.1 A for the expanded and compact VLP and virus particles by image reconstruction. These structures can be used in designing mutations increasing the stability and immunogenicity of CVB1-VLP in the future. Overall, our results highlight the potential of using formalin inactivated CVB1 vaccine in mucosal immunization programs and provide important information for future development of VLP-based vaccines against all enteroviruses.

Evaluation of Formalin-Inactivated Vaccine Efficacy against Red Seabream Iridovirus (RSIV) in Laboratory and Field Conditions.

Red seabream iridovirus (RSIV) is a major cause of marine fish mortality in Korea, with no effective vaccine available since its first occurrence in the 1990s. This study evaluated the efficacy of a formalin-killed vaccine against RSIV in rock bream under laboratory and field conditions. For the field trial, a total of 103,200 rock bream from two commercial marine cage-cultured farms in Southern Korea were vaccinated. Farm A vaccinated 31,100 fish in July 2020 and monitored them for 18 weeks, while farm B vaccinated 30,700 fish in August 2020 and monitored them for 12 weeks. At farm A, where there was no RSIV infection, the vaccine efficacy was assessed in the lab, showing a relative percentage of survival (RPS) ranging from 40% to 80%. At farm B, where natural RSIV infections occurred, cumulative mortality rates were 36.43% in the vaccinated group and 80.32% in the control group, resulting in an RPS of 54.67%. The RSIV-infectious status and neutralizing antibody titers in serum mirrored the cumulative mortality results. This study demonstrates that the formalin-killed vaccine effectively prevents RSIV in cage-cultured rock bream under both laboratory and field conditions.

A novel vaccine strategy using quick and easy conversion of bacterial pathogens to unnatural amino acid-auxotrophic suicide derivatives.

Live vaccines are the oldest vaccines with a history of more than 200 years. Due to their strong immunogenicity, live vaccines are still an important category of vaccines today. However, the development of live vaccines has been challenging due to the difficulties in achieving a balance between safety and immunogenicity. In recent decades, the frequent emergence of various new and old pathogens at risk of causing pandemics has highlighted the need for rapid vaccine development processes. We have pioneered the use of uAAs to control gene expression and to conditionally kill host bacteria as a biological containment system. This report proposes a quick and easy conversion of bacterial pathogens into live vaccine candidates using this containment system. The balance between safety and immunogenicity can be modulated by the selection of the genetic devices used. Moreover, the uAA-auxotrophy can prevent the vaccine from infecting other individuals or establishing the environment.

Safety, tolerability and immunogenicity of PRV-101, a multivalent vaccine targeting coxsackie B viruses (CVBs) associated with type 1 diabetes: a double-blind randomised placebo-controlled Phase I trial

Aims/hypothesisInfection with coxsackie B viruses (CVBs) can cause diseases ranging from mild common cold-type symptoms to severe life-threatening conditions. CVB infections are considered to be prime candidates for environmental triggers of type 1 diabetes. This, together with the significant disease burden of acute CVB infections and their association with chronic diseases other than diabetes, has prompted the development of human CVB vaccines. The current study evaluated the safety and immunogenicity of the first human vaccine designed against CVBs associated with type 1 diabetes in a double-blind randomised placebo-controlled Phase I trial.MethodsThe main eligibility criteria for participants were good general health, age between 18 and 45 years, provision of written informed consent and willingness to comply with all trial procedures. Treatment allocation (PRV-101 or placebo) was based on a computer-generated randomisation schedule and people assessing the outcomes were masked to group assignment. In total, 32 participants (17 men, 15 women) aged 18–44 years were randomised to receive a low (n=12) or high (n=12) dose of a multivalent, formalin-inactivated vaccine including CVB serotypes 1–5 (PRV-101), or placebo (n=8), given by intramuscular injections at weeks 0, 4 and 8 at a single study site in Finland. The participants were followed for another 24 weeks. Safety and tolerability were the primary endpoints. Anti-CVB IgG and virus-neutralising titres were analysed using an ELISA and neutralising plaque reduction assays, respectively.ResultsAmong the 32 participants (low dose, n=12; high dose, n=12; placebo, n=8) no serious adverse events or adverse events leading to study treatment discontinuation were observed. Treatment-emergent adverse events considered to be related to the study drug occurred in 37.5% of the participants in the placebo group and 62.5% in the PRV-101 group (injection site pain, headache, injection site discomfort and injection site pruritus being most common). PRV-101 induced dose-dependent neutralising antibody responses against all five CVB serotypes included in the vaccine in both the high- and low-dose groups. Protective titres ≥8 against all five serotypes were seen in >90% of participants over the entire follow-up period.Conclusions/interpretationThe results indicate that the tested multivalent CVB vaccine is well tolerated and immunogenic, supporting its further clinical development.Trial registrationClinicalTrials.gov NCT04690426.FundingThis trial was funded by Provention Bio, a Sanofi company.Graphical

Vaccines for prevention of respiratory syncytial virus infection

Respiratory syncytial virus is a virus that causes infections in lower respiratory tract among infants aged under 5 years old, older adults aged above 65 years old and populations with other potential complications. Some susceptible populations to RSV may develop pneumonia and bronchiolitis. The mechanism of RSV virus transmission is through air droplets. The burden of hospitalization causes by the infection of RSV is severe and episodic, with the prevalence mainly concentrated in winter periods. The development of vaccines against RSV virus statutes in the early 1960s, but was paused and halted due to the failure of formalin inactivated vaccine. The current study first reviewed the prevalence, structure, mechanism and development history of RSV and its vaccines, following which the present work focus on a summary of the results of clinical trials of vaccines against RSV on different groups of populations, especially those with special condition, such as older adult and pregnant women.

Immune responses and protective efficacy of American eel (Anguilla rostrata) immunized with a formalin-inactivated vaccine against Anguillid herpesvirus

Anguillid herpesvirus 1 (AngHV), the causative agent of "mucus sloughing and hemorrhagic septicemia disease", causes serious infectious diseases in farmed eel. Among the effective prevention and control strategies, vaccination is one of the most effective approaches. However, no vaccine for AngHV is available. Our study developed a formalin-inactivated AngHV vaccine and evaluated its performance in American eels. Initially, AngHV-FJ, a strain of AngHV, was inactivated completely by 0.1 % formaldehyde, mixed with adjuvant Montanide ISA 763 A VG (763A). Then, vaccines containing different amount of antigen (3 × 106 PFU, 3 × 105 PFU, 3 × 104 PFU, 3 × 103 PFU) were immunized in each American eels. The results showed that the 3 × 105 PFU/fish was the proper dose. The inactivated AngHV vaccine was proven safe for American eels by back intramuscular injection. The results of twice immunization showed that antibody production peaked in the 8th week after the first immunization, and the antibody titer was 1:64,000. Furthermore, the immunized fishes challenged with AngHV (105 PFU/ml immersion) showed a significantly lower incidence rate (33.33 %) than the control group (95.65 %). The survival of the fish in the vaccine group (94.44 %) was significantly higher than the control group (60.87 %). The relative survival rate of the vaccinated group was 85.80 %. Also, vaccine group tissue collected at 7th d post-challenge showed reduced tissue damage and a lower virus load than the control group. The expression of cytokines of IL-1β, IFN-α, IFN-γ, Mx1, RIG-1, and IRF-3, were significantly lower in the vaccine group than the control group at the 7th and 14th d post-challenge. Overall, the formalin-inactivated AngHV vaccine was safe and had immune protective effects against AngHV infection.

The stability and immunogenicity of formalin-inactivated Enterovirus A71 whole virion vaccine after ten years of low temperature storage

BackgroundVaccine stability is an important issue for vaccine development, which affects whether the vaccine product is effective within a certain period of time in each progress. Hand, foot, and mouth diseases (HFMD) is an epidemic disease in young children usually caused by Enterovirus A group viruses, and the Enterovirus A71 (EV-A71) had caused several pandemics and public health issues around the world. After two decades of research and development, formalin-inactivated EV-A71 (FI-EV-A71) vaccines are the first to complete the phase III clinical trials for protection against EV-A71 infection. Currently, the shelf life of FI-EV-A71 vaccine product is set to be within 18 months, but the stability and the effectiveness of the FI-EV-A71 whole virion when stored long-term at low temperature remains undetermined. MethodsAssessing the long-term storage properties of viral particles facilitates flexibility in manufacturing of vaccine products. In this study, the stability profiles of FI-EV-A71 vaccine lots and bulks after long-term of low temperature storage were analyzed by protein tests, particle measurement and animal immunization study. ResultsAfter over ten years of storage, the reduction of protein concentration in the FI-EV-A71 bulk samples is less than 30 % and the antigenic content remained in a suspended, particulate state. Both the packed FI-EV-A71 final vaccine products and the FI-EV-A71 antigens adjuvant premix bulk could elicit strong neutralizing responses in mice. ConclusionAfter ten years of low temperature storage, the FI-EV-A71 vaccine still presents decent stability and good immunogenicity.

Respiratory Syncytial Virus Vaccines: A Review of the Candidates and the Approved Vaccines.

Respiratory syncytial virus (RSV) is responsible for a significant proportion of global morbidity and mortality affecting young children and older adults. In the aftermath of formalin-inactivated RSV vaccine development, the effort to develop an immunizing agent was carefully guided by epidemiologic and pathophysiological evidence of the virus, including various vaccine technologies. The pipeline of RSV vaccine development includes messenger ribonucleic acid (mRNA), live-attenuated (LAV), subunit, and recombinant vector-based vaccine candidates targeting different virus proteins. The availability of vaccine candidates of various technologies enables adjustment to the individualized needs of each vulnerable age group. Arexvy® (GSK), followed by Abrysvo® (Pfizer), is the first vaccine available for market use as an immunizing agent to prevent lower respiratory tract disease in older adults. Abrysvo is additionally indicated for the passive immunization of infants by maternal administration during pregnancy. This review presents the RSV vaccine pipeline, analyzing the results of clinical trials. The key features of each vaccine technology are also mentioned. Currently, 24 vaccines are in the clinical stage of development, including the 2 licensed vaccines. Research in the field of RSV vaccination, including the pharmacovigilance methods of already approved vaccines, promotes the achievement of successful prevention.

Influenza breakthrough infection in vaccinated mice is characterized by non-pathological lung eosinophilia.

Eosinophils are important mediators of mucosal tissue homeostasis, anti-helminth responses, and allergy. Lung eosinophilia has previously been linked to aberrant Type 2-skewed T cell responses to respiratory viral infection and may also be a consequence of vaccine-associated enhanced respiratory disease (VAERD), particularly in the case of respiratory syncytial virus (RSV) and the formalin-inactivated RSV vaccine. We previously reported a dose-dependent recruitment of eosinophils to the lungs of mice vaccinated with alum-adjuvanted trivalent inactivated influenza vaccine (TIV) following a sublethal, vaccine-matched H1N1 (A/New Caledonia/20/1999; NC99) influenza challenge. Given the differential role of eosinophil subset on immune function, we conducted the investigations herein to phenotype the lung eosinophils observed in our model of influenza breakthrough infection. Here, we demonstrate that eosinophil influx into the lungs of vaccinated mice is adjuvant- and sex-independent, and only present after vaccine-matched sublethal influenza challenge but not in mock-challenged mice. Furthermore, vaccinated and challenged mice had a compositional shift towards more inflammatory eosinophils (iEos) compared to resident eosinophils (rEos), resembling the shift observed in ovalbumin (OVA)-sensitized allergic control mice, however without any evidence of enhanced morbidity or aberrant inflammation in lung cytokine/chemokine signatures. Furthermore, we saw a lung eosinophil influx in the context of a vaccine-mismatched challenge. Additional layers of heterogeneity in the eosinophil compartment were observed via unsupervised clustering analysis of flow cytometry data. Our collective findings are a starting point for more in-depth phenotypic and functional characterization of lung eosinophil subsets in the context of vaccine- and infection-induced immunity.

The third pandemic: The respiratory syncytial virus landscape and specific considerations for the allergist/immunologist.

Background: Since its initial identification in 1956, respiratory syncytial virus (RSV) has been the second most common cause of mortality in infants <6 months of age and a major cause of morbidity and mortality associated with lower respiratory tract infection (LRTI) in older adults (ages >60 years) worldwide. Of particular interest to the allergist/immunologist is a growing body of evidence that suggests an association between LRTI caused by RSV in infants with later-life development of asthma, wheezing, or impaired lung function in adults. Efforts to develop a RSV vaccine have been thwarted for >70 years by the occurrence of enhanced respiratory disease (ERD), an adverse RSV vaccine reaction, in the 1960s, in which more-severe illness occurred on natural infection after vaccination of infants who were RSV naive and with a formalin-inactivated RSV vaccine. Recent advances in knowledge of the structural biology of the RSV surface fusion glycoprotein, however, have revolutionized RSV vaccine development for preventive interventions and have offered, at last, the hope of an effective and safe vaccine for the prevention of RSV disease. Objective: The purpose of this report was to examine the current evidence that supports the epidemiology, disease manifestations, molecular biology, treatments, and new vaccine development of RSV vaccines. Results: The host-immune response to RSV infection is carried out by two distinct but overlapping universes of mucosal and systemic immune systems in which a balanced set of B- and T-cell responses are involved in protective immunity that includes the mucosal immune system in which immunoglobulin A (IgA) prevails and the systemic immune system in which IgG neutralizing antibody predominates. The key to developing an effective vaccine is now thought to be linked to the availability of a stabilized prefusion F protein in the immunizing vaccine, which can perform a dual function of a balanced mucosal and/or systemic immune response as well as an effective antibody specifically directed to critical epitopes on the requisite prefusion F protein. Conclusion: The unfortunate manifestation of RSV ERD that occurred in the 1960s has led to a better understanding of the structural biology of the RSV surface fusion glycoprotein and has provided a basis for the development of more effective and safer RSV vaccines and monoclonal antibody preparations for immunoprophylaxis of the dread effects of RSV disease. There are now a large number of clinical trials in progress that are evaluating these products, which include recombinant vector, subunit, particle-based, live-attenuated, chimeric, and nucleic acid vaccines; and monoclonal antibodies. This article gives an overview of the many aspects of RSV disease and development of virus (RSV) vaccines of particular interest to the allergist/immunologist.

Multivalent vaccines demonstrate immunogenicity and protect against Coxiella burnetii aerosol challenge.

Vaccines are among the most cost-effective public health measures for controlling infectious diseases. Coxiella burnetii is the etiological agent of Q fever, a disease with a wide clinical spectrum that ranges from mild symptoms, such as fever and fatigue, to more severe disease, such as pneumonia and endocarditis. The formalin-inactivated whole-cell vaccine Q-VAX® contains hundreds of antigens and confers lifelong protection in humans, but prior sensitization from infection or vaccination can result in deleterious reactogenic responses to vaccination. Consequently, there is great interest in developing non-reactogenic alternatives based on adjuvanted recombinant proteins. In this study, we aimed to develop a multivalent vaccine that conferred protection with reduced reactogenicity. We hypothesized that a multivalent vaccine consisting of multiple antigens would be more immunogenic and protective than a monovalent vaccine owing to the large number of potential protective antigens in the C. burnetii proteome. To address this, we identified immunogenic T and B cell antigens, and selected proteins were purified to evaluate with a combination adjuvant (IVAX-1), with or without C. burnetii lipopolysaccharide (LPS) in immunogenicity studies in vivo in mice and in a Hartley guinea pig intratracheal aerosol challenge model using C. burnetii strain NMI RSA 493. The data showed that multivalent vaccines are more immunogenic than monovalent vaccines and more closely emulate the protection achieved by Q-VAX. Although six antigens were the most immunogenic, we also discovered that multiplexing beyond four antigens introduces detectable reactogenicity, indicating that there is an upper limit to the number of antigens that can be safely included in a multivalent Q-fever vaccine. C. burnetii LPS also demonstrates efficacy as a vaccine antigen in conferring protection in an otherwise monovalent vaccine formulation, suggesting that its addition in multivalent vaccines, as demonstrated by a quadrivalent formulation, would improve protective responses.

Dry- down probe free qPCR for detection of KFD in resource limited settings.

Kyasanur Forest Disease is a tick-borne flavivirus is endemic in the Southern India. The recent expansion and resurgence of sporadic outbreaks in southern parts of country is the most important concern. Although only formalin inactivated vaccine is available for treatment with limited efficacy the early detection and timely identification is a only way to prevent spread of cases. If the disease can be identified prior to infection in humans like in forest areas from ticks and vectors the disease spread supposed to be managed quickly. Here we have standardized a single tube ready to use dry-down probe free real time RT-PCR targeted against virus envelope gene for detection of KFDV infection. The assay was standardized in liquid format first, later it was converted into dry-down format with addition of stabilizers with a similar sensitivity and specificity (10RNA Copies/rxn). The sensitivity was comparable to the most widely used and accepted diagnostic platform i.e. TaqMan qRT-PCR. However as the reported assay here omit the need of probes makes it cost effective and dry-down reagents makes more stability to the developed assay in this study if compare to TaqMan qPCR. The assay was evaluated with KFD positive samples and healthy sample panel which revealed high concordance with TaqMan qRT-PCR. Stability was unaffected by temperature fluctuations during transportation even in cold chain free conditions, thus reduce the maintenance of strict cold storage. These findings demonstrated that the reported assay is convenient with 100% sensitivity and specificity to TaqMan qPCR. Thus this assay has the potential usefulness for diagnosis KFDV for routine surveillance in resource limited laboratory settings omitting the use costly and heat sensitive TaqMan qRT-PCR reagents without compromising the sensitivity and specificity of the diagnosis assay.

Influenza vaccine is able to prevent neuroinflammation triggered by H7N7 IAV infection.

Influenza A virus (IAV) subtypes are a major cause of illness and mortality worldwide and pose a threat to human health. Although IAV infection is considered a self-limiting respiratory syndrome, an expanded spectrum of cerebral manifestations has been reported following IAV infection. Neurotropic IAVs, such as the H7N7 subtype, are capable of invading the central nervous system (CNS) and replicating in brain cells, resulting in microglia-induced neuroinflammation. Microglial cells, the brain's resident immune cells, are instrumental in the inflammatory response to viral infection. While activation of microglia is important to initially contain the virus, excessive activation of these cells leads to neuronal damage. Previous studies have shown that acute and even long-term IAV-induced neuroinflammation leads to CNS damage. Therefore, the search for possible preventive or therapeutic strategies is of great importance. In this study, we investigated the potential effect of vaccination against acute neuroinflammation induced by H7N7 infection and subsequent neuronal damage in the hippocampus, a particularly vulnerable brain region, comparing young and aged mice. Immunosenescence is one of the striking pathophysiological changes during mammalian aging that leads to "inflammaging" and critically limits the protection by vaccines in the elderly. The results suggest that formalin-inactivated H7N7 vaccine has a preventive effect against the inflammatory responses in the periphery and also in the CNS after H7N7 infection. Cytokine and chemokine levels, increased microglial density, and cell volume after H7N7 infection were all attenuated by vaccination. Further structural analysis of microglial cells also revealed a change in branching complexity after H7N7 infection, most likely reflecting the neuroprotective effect of the vaccination. In addition, synapse loss was prevented in vaccinated mice. Remarkably, engulfment of post-synaptic compartments by microglia can be proposed as the underlying mechanism for spine loss triggered by H7N7 infection, which was partially modulated by vaccination. Although young mice showed better protection against neuroinflammation and the resulting deleterious neuronal effects upon vaccination, a beneficial role of the vaccine was also observed in the brains of older mice. Therefore, vaccination can be proposed as an important strategy to prevent neurological sequelae of H7N7 infection.

Propagation and immunological characterization of coxsackievirus A10 in a serum-free HEK293A cell culture system

Coxsackievirus A10 (CVA10) is one of enteroviral pathogens that cause the hand, foot, and mouth disease (HFMD). Since CVA10 was reported to be not easily propagated in the Vero cell culture, a feasible manufacture process for producing formalin-inactivated CVA10 vaccine is urgently needed. Several cell lines that commonly used for viral vaccine production was tested for CVA10 (M2014 strain) culture in this study, and our result showed that CVA10 could be easily propagated in the HEK293A cells. A serum-free HEK293A cell culture system was developed for CVA10 production and the yields have reached over 108 TCID50/mL. The biochemical and immunogenic properties of CVA10 particles obtained from this serum-free HEK293A culture were identical to our previous study. Two major particles of CVA10 were separated by ultracentrifugation, and only the infectious mature particles were capable of inducing CVA10 neutralizing antibody responses in the mouse immunogenicity studies. Additionally, we found that coxsackievirus A6 and enterovirus A71 could also be easily propagated using this serum-free HEK293A cell culture system. Our results provide a solution to overcome the obstacle in the propagation of CVA10 and facilitate the development of multivalent vaccines for prevention of HFMD.

Molecular mechanisms of the virulence and efficacy of a highly virulent Vibrio anguillarum strain and its formalin-inactivated vaccine in rainbow trout.

In this study, we have isolated four strains of Vibrio anguillarum, revealing that they share the same serotype of O1, biochemical characteristics and virulence factor genes. However, there were differences in haemolytic activity among the bacterial strains; a strain with lower pathogenicity showed γ-haemolytic activity, whereas other virulent strains showed α-haemolytic activity on blood agar and higher empA gene expression in RTG-2 cell line. The most virulent strain was V. anguillarum RTBHR from diseased masu salmon (Oncorhynchus masou), which resulted in mortality of 100% and 93.3% when injected intraperitoneally at concentrations of 9 × 105 and 6.3 × 105 colony-forming units/fish in rainbow trout (Oncorhynchus mykiss) and Coho salmon (Oncorhynchus kisutch), respectively. A formalin-inactivated vaccine of V. anguillarum RTBHR induced a protective and specific immunity in rainbow trout as the vaccinated fish exhibited low cumulative mortality in a challenge test and a high specific antibody response in enzyme-linked immunosorbent assay at 8 weeks post-vaccination. The produced antibody was bound to bacterial proteins of 30-37 kDa in size. This adaptive immune response was detected as early as day 1, with quantitative polymerase chain reaction analysis revealing the upregulated expression of genes encoding for TCRα, T-bet, mIgM and sIgM in rainbow trout. This suggested that the vaccine inducedT (probably a more dominant Th1 response) and B cell responses. In conclusion, the vaccine successfully protected fish from V. anguillarum infection by eliciting cellular and humoral immune responses.

Mycobacterium bovis BCG Given at Birth Followed by Inactivated Respiratory Syncytial Virus Vaccine Prevents Vaccine-Enhanced Disease by Promoting Trained Macrophages and Resident Memory T Cells.

Respiratory syncytial virus (RSV) infects more than 60% of infants in their first year of life. Since an experimental formalin-inactivated (FI) RSV vaccine tested in the 1960s caused enhanced respiratory disease (ERD), few attempts have been made to vaccinate infants. ERD is characterized by Th2-biased responses, lung inflammation, and poor protective immune memory. Innate immune memory displays an increased nonspecific effector function upon restimulation, a process called trained immunity, or a repressed effector function upon restimulation, a process called tolerance, which participates in host defense and inflammatory disease. Mycobacterium bovis bacillus Calmette-Guérin (BCG) given at birth can induce trained immunity as well as heterologous Th1 responses. We speculate that BCG given at birth followed by FI-RSV may alleviate ERD and enhance protection through promoting trained immunity and balanced Th immune memory. Neonatal mice were given BCG at birth and then vaccinated with FI-RSV+Al(OH)3. BCG/FI-RSV+Al(OH)3 induced trained macrophages, tissue-resident memory T cells (TRM), and specific cytotoxic T lymphocytes (CTL) in lungs and inhibited Th2 and Th17 cell immune memory, all of which contributed to inhibition of ERD and increased protection. Notably, FI-RSV+Al(OH)3 induced tolerant macrophages, while BCG/FI-RSV+Al(OH)3 prevented the innate tolerance through promoting trained macrophages. Moreover, inhibition of ERD was attributed to trained macrophages or TRM in lungs but not memory T cells in spleens. Therefore, BCG given at birth to regulate trained immunity and TRM may be a new strategy for developing safe and effective RSV killed vaccines for young infants. IMPORTANCE RSV is the leading cause of severe lower respiratory tract infection of infants. ERD, characterized by Th2-biased responses, inflammation, and poor immune memory, has been an obstacle to the development of safe and effective killed RSV vaccines. Innate immune memory participates in host defense and inflammatory disease. BCG given at birth can induce trained immunity as well as heterologous Th1 responses. Our results showed that BCG/FI-RSV+Al(OH)3 induced trained macrophages, TRM, specific CTL, and balanced Th cell immune memory, which contributed to inhibition of ERD and increased protection. Notably, FI-RSV+Al(OH)3 induced tolerant macrophages, while BCG/FI-RSV+Al(OH)3 prevented tolerance through promoting trained macrophages. Moreover, inhibition of ERD was attributed to trained macrophages or TRM in lungs but not memory T cells in spleens. BCG at birth as an adjuvant to regulate trained immunity and TRM may be a new strategy for developing safe and effective RSV killed vaccines for young infants.

Does the rise in cases of Kyasanur forest disease call for the implementation of One Health in India?

The viral hemorrhagic illness known as Kyasanur forest disease (KFD), also referred to as monkey fever, is transmitted by ticks. The etiological agent, which was formerly isolated from monkeys, is Kyasanur forest disease virus (KFDV), an RNA virus belonging to the family Flaviviridae. Since 1957, India has reported 400–500 cases annually, with a case fatality rate of 1–3%. Shiroma, Chikkamagalore, Uttara Kannada, Dakshina Kannada, and Udupi are the five regions in Karnataka, India where KFD is highly prevalent, with around 3263 notified cases reported between 2003 and 2012, of which 823 cases were laboratory confirmed.The symptoms of monkey fever can range from mild sickness to severe neurological sequelae. Currently, prophylaxis involves administration of formalin-inactivated tissue culture vaccine. Despite the continuing vaccination programs in endemic areas for KFD, new cases are being reported. The current availability and effectiveness of the vaccine are not enough to provide protective immunity and thus prevent new outbreaks.Our study examined the known literature, knowledge gaps, and host responses associated with KFD. There is a need for robust vector control, public awareness campaigns, mass vaccination programmes, a full understanding of the eco-epidemiological elements of the disease, and implementation of a One Health program. These could all support prevention and management protocols, and thus help to address the issue.

Efficacy and transcriptome analysis of golden pompano (Trachinotus ovatus) immunized with a formalin-inactived vaccine against Streptococcus iniae

Streptococcus iniae is a worldwide fish pathogen that cause tremendous economic losses to the global aquaculture industry. Vaccination is regarded as the most effective and safe way to control fish diseases. In our study, we developed a formalin-inactivated vaccine against S. iniae and evaluated its effect in golden pompano (Trachinotus ovatus). In addition, in order to clarify the molecular mechanisms underlying the vaccine protection, we compared the spleen transcriptomes of vaccinated and unvaccinated golden pompano at 1, 2 and 7 d post vaccination using the RNA-seq technology. The relative percentage survival (RPS) reached 71.1% at 28 days post-vaccination which suggested that the vaccine provided highly protection against S. iniae. KEGG pathway analysis revealed that phagosome, cytokine-cytokine receptor interaction, MAPK signaling pathway, and CAMs were activated by the vaccine. The most of strongly up-regulated genes in golden pompano spleen are involving in innate immunity. For adaptive immunity, the vaccine evoked a CD8+ CTL-mediated response by MHC Ⅰ pathway to achieve immune protection.