Randomized, blind, controlled phase III clinical trial: Assessing the immunogenicity and safety of freeze-dried human rabies vaccine (vero cell) with a 4-dose regimen (2-1-1) in a 10-60 year-old demographic.

OBJECTIVE: The aim of this study is to demonstrate that the freeze-dried human rabies vaccine (Vero cell), administered in a four-dose schedule (2-1-1) to the 10-60 years old population, has immunogenicity that is not inferior to the approved five-dose schedule and similar vaccines with a four-dose schedule, and to evaluate its safety. METHOD: A total of 1800 individuals were enrolled and divided into three groups: four-dose test group, four-dose control group, and five-dose control group. The rabies virus neutralizing antibodies were measured using the Rapid Fluorescent Focus Inhibition Test to assess immunogenicity, and the incidence of adverse events and serious adverse events were statistically analyzed. RESULTS: The seroconversion rates 14 days after the first dose and 14 days after the complete course of vaccination were 100% in all three groups. The antibody GMC of the four-dose test group was higher than that of the five-dose control group, but slightly lower than the four-dose control group. Seven days after the first dose, both four-dose regimen groups showed higher seroconversion rates and antibody GMCs compared to the five-dose regimen group, proving that the immunogenic effect of the four-dose regimen seven days post-first vaccination is superior to the five-dose regimen. The overall incidence of adverse events showed no significant difference between the four-dose test group and the five-dose control group, but was significantly lower in the four-dose test group compared to the four-dose control group. CONCLUSION: The vaccine in the four-dose test group is equivalent in immunogenic effect to the four-dose control group vaccine and superior to the five-dose control group vaccine; the safety of the vaccine in the four-dose test group is equivalent to the five-dose control group vaccine and superior to the four-dose control group vaccine. CLINICALTRIALS: gov number: NCT05549908.

A rare skin reaction in an elderly woman after exposure to prophylaxis for rabies: A case report.

Introduction: Rabies is a zoonosis caused by viruses of the family Rhabdoviridae. Prophylaxis with the rabies vaccine and immunoglobulins, depending on the severity of the case, is recommended. After vaccination, mild, moderate, or severe adverse events (AE) are described. Although rare, severe skin reactions may occur, increasing the risk of anaphylaxis. Case report: An 84-year-old woman was attacked by a stray unknown cat, leaving her with bites and scratches in the neck region and multiple injuries. The case was classified as severe. About 3 h after the first dose of the rabies vaccine, disseminated purplish spots appeared on her lower limbs, worsening significantly after the second dose, requiring hospitalization for the application of the third dose under observation, dermatology evaluation, and collection of skin tissue for biopsy. She was discharged 24 h after the third vaccination, and the purple spots cleared gradually. The biopsy suggested an adverse reaction to the vaccine components. Immunohistochemistry of the rabies virus antigen in dermal nerve fillets was negative. The seroconversion post rabies vaccine showed IgG antibody values below the reference levels. Conclusion: Vaccination against rabies is extremely important; however, AEs may occur. Our patient developed an important AE and required hospitalization. After complete vaccination, the serum was not converted. A similar case was not previously described, and the case report is important for the creation of jurisprudence on rabies vaccination in elderly patients in Brazil.

Study on immune persistence of the CTN-1V strain rabies vaccine in humans.

This study is a single-arm, single-center phase IV clinical trial on a rabies vaccine that has been marketed in China. The Vero cells and CTN-1V strain are used in the rabies vaccine product. The purpose of this study was to investigate the safety, immunogenicity and immune persistence of this product. One hundred and forty-nine participants were enrolled to the study, all of whom were included in the safety analysis set (SS), among which 116 participants were included in the protocol analysis set (PPS), One hundred and fifteen participants were included in the 6-month immune persistence analysis set (IPS6) and 111 in the 12-month immune persistence analysis set IPS12. Results showed that: 1) In the SS analysis set, adverse reactions were mainly pyrexia and pain at the vaccination site, the severity of which were mostly grade 1, and concentrated in 0-3 days after vaccination. No grade 3 or above adverse events and serious adverse events (SAE) related to the experimental vaccine were observed. 2) In the PPS analysis set, the antibody positive conversion rate reached 100% at 14 days after full immunization of the pre-immunized negative population; The antibody geometric mean titer (GMT) (95% CI) was 14.82 (13.00, 16.90). 3) The positive rate of serum neutralizing antibody was 93.91 % and the GMT at 1.58 IU/ml at 6 months after full immunization. The positive rate of neutralizing antibody was 85.59 % and GMT at 1.30 IU/ml at 12 months after immunization. Our results show that the human rabies vaccine with the CTN-1V strain and Vero cells as matrix had good safety, immunogenicity and immune persistence in our study.

Factors Involved in the Immunological Protection against Rabies Virus in Dogs in Spain.

Rabies, a viral disease spread by infected animal bites that causes encephalitis in humans and other mammals, is a neglected infectious disease present on all continents except Antarctica. Spain has been free of terrestrial rabies since 1978. However, due to its geographical situation, it represents a bridge for imported cases from an endemic continent such as Africa to Europe. Rabies vaccination in dogs is an essential preventive tool against this zoonosis. The aim of this study was to determine the state of the immune response against rabies virus in dogs in Spain and to demonstrate whether several factors that have been previously related to the influence of the seroprevalence of this species are involved here. The seroconversion level of this zoonotic virus was assessed in a total of 1060 animals. Indirect ELISA was used to obtain data for statistical analysis to evaluate the studied variables. Working under the concept of One Health, this study provides relevant information to be taken into consideration not only to prevent re-emergence in countries free of this disease but also for prevention and control in endemic countries.

Rabies post-exposure prophylaxis in the emergency department.

STUDY OBJECTIVES: Rabies is a zoonotic single-stranded RNA lyssavirus that can cause acute infections of the central nervous system (CNS) including encephalomyelitis, encephalitis, and meningoencephalitis that is progressively fatal. Rabies is more common in developing countries, but approximately 23,000 people in the United States (US) are estimated to have been exposed or to have received post exposure prophylaxis (PEP) yearly. Nebraska Medicine follows the Advisory Committee on Immunization Practices (ACIP) guidelines for the vaccination series, as well as the 20 units/kg administration of immunoglobulin (RIG). Nebraska Medicine Medical Center (NMC) and Bellevue Medical Center (BMC) treat the scheduling of the complete rabies vaccine series differently. At both campuses, patients receive their immunoglobulin and first vaccine in the Emergency Department (ED). At NMC, patients are scheduled to receive the remainder of their vaccination series at the outpatient infusion center by the ED pharmacist. At BMC, the subsequent vaccinations are given as "Nurse Only" return visits to the ED. The objective of this study was to compare patient compliance of two different processes for follow-up rabies vaccine series completion. This project's primary aim was to determine the rate of patient compliance for follow up rabies vaccine doses. The secondary aims of this project were to determine if there was a difference in patient follow-up compliance between the two campuses, patient specific factors that impact compliance, and potential cost savings if a dose rounding protocol for RIG was utilized. METHODS: This retrospective chart review was completed as a quality improvement project. Data from patients who had received either rabies immunoglobulin and/or a rabies vaccine, were >18 years of age, and were not admitted were collected for a 3-year period from July 1, 2019, to June 30, 2022. Data were abstracted from the patient's EMR (electronic medical records) using a SQL (Structured query language) query of pre-identified data elements. When unable to abstract with SQL query, data elements were manually abstracted. All data abstracted was collated and descriptive analysis performed. RESULTS: A total of 723 individual encounters were identified during the study period. After combining rabies series for each individual patient, 173 unique patients remained. After exclusions were applied, 143 patients were included: 104 patients from NMC, and 39 from BMC. For the primary outcome, appropriate completion between the two campuses was 78.3%. When comparing the two campuses, completion rates were higher at NMC (82% vs. 69%), although not statistically significant (p = 0.12). Appropriate completion of vaccine series was statistically significant for both payor and exposure type. Application of a dose rounding policy with those >45 kg, rounding to the nearest vial, as well as rounding down if at the midpoint interval, 56 fewer vials would have been used between the two campuses. This would have resulted in a potential cost savings of $57,928.64 over the study period.

Potency, immunogenicity, and efficacy of rabies vaccine: In vitro and in vivo approach.

BACKGROUND: Rabies, a potentially lethal virus, affects more than 150 countries. Although the rabies vaccine and immunoglobulin have been available since 1908, Bangladesh is new to vaccine manufacturing. We checked the quality of the local manufacturing rabies vaccine for substandard. METHODS: The potency and immunogenicity of 20 vaccines were analyzed by three in vivo and in vitro methods from March 2020 to May 2023. Single radial immunodiffusion, fluorescent antibody virus neutralization, and national institutes of health tests were carried out to evaluate the vaccine's efficacy to provide sufficient protection against the rabies virus. RESULTS: The potency of the rabies vaccine was determined by the in vitro SRID method by measuring glycoprotein content. An average of 16 articles from each batch was calculated. The minimum and maximum average mean values of the 20 batches were 5.058 and 5.346, respectively. The variance was calculated at 0.00566. We found a coefficient of variation (CV) between 9.36% and 14.80%. The 100% sample was satisfactory, as these samples had a potency of over 2.5 IU/mL. To observe immunogenicity, we applied the FAVN method for determining antibody titers. An average of 16 articles from every batch were counted to quantify antibody titers. The mean quantity of antibody titers ranged from 2.389 to 3.3875. The CV was slightly lower because of the dispersion of the data. At last, we performed an in vivo method, the NIH test method, to determine potency based on mortality rate. We found a mean value of 4.777 IU/SHD with a standard deviation of 1.13 IU/SHD. All 20 batches were found 100% satisfactory in the NIH test. CONCLUSION: The study implies that the rabies human vaccines manufactured in Bangladesh are potent enough to provide sufficient immunogenicity. Our research is warranted testimony for healthcare providers who work to extirpate rabies.

Adjuvant activity of cordycepin, a natural derivative of adenosine from Cordyceps militaris, on an inactivated rabies vaccine in an animal model.

Vaccination is the most feasible way of preventing rabies, an ancient zoonosis that remains a major public health concern globally. However, administration of inactivated rabies vaccination without adjuvants is always inefficient and necessitates four to five injections. In the current study, we explored the adjuvant characteristics of cordycepin, a major bioactive component of Cordyceps militaris, to boost immune responses against a commercially available rabies vaccine. We found that cordycepin could stimulate stronger phenotypic and functional maturation of dendritic cells (DCs). For animal experiments, mice were immunized 3 times with rabies vaccine in the presence or absence of cordycepin at 1-week interval. Analysis of T cell differentiation and serum antibody isotypes showed that humoral immunity was dominant with a Th2 biased immune response. These results were also supported by the raised ratio of follicular helper T cells (TFH) and germinal center B cells (GCB). Thus, titer of rabies virus neutralizing antibody (RVNAb) and rabies virus-specific memory B cells were both raised as a result. Furthermore, administration of cordycepin did not cause pathological phenomena or body weight loss. The findings indicate that cordycepin could be used as a promising adjuvant for rabies vaccines to get a higher range of protection without any side effects.

Rabies post-exposure prophylaxis delivery to ensure treatment efficacy and increase compliance.

Objectives: Since rabies is lethal once symptoms appear, its prevention including community awareness, mass dog vaccination and post-exposure prophylaxis (PEP) is crucial. Although safe and potent rabies vaccines have long been available, the global rabies burden is still high and access to adequately-delivered PEP remains challenging. Here we offer healthcare providers up-to-date, simple, exhaustive, visual guidance on how to perform PEP steps correctly. Protocol: PEP consists of 1) washing the wound with water and soap for 15 min, 2) assessing the need for rabies biologicals based on specific criteria; 3) administering, if required, rabies immunoglobulin or monoclonal antibodies deep in and around all wounds; 4) starting, if necessary, the WHO-recommended intradermal 1-week vaccination regimen; 5) informing patients adequately throughout the PEP process to increase compliance and avoid dangerous misconceptions about animal bite treatment and rabies risk. Discussion: The intradermal 1-week vaccination regimen recommended by WHO is as safe as other regimens but carries important cost-, dose- and time-sparing benefits. As fundamental as the correct administration of rabies biologicals is clear doctor-patient communication and sharing of up-to-date knowledge among healthcare professionals. Conclusions: This resource will help ensuring that no life is lost to rabies, an incurable yet preventable disease.

Impacts of shelter management on canine rabies immune status.

Rabies vaccination is mandatory in dogs in Thailand. In this study, shelter management quality and rabies immune status were evaluated by questionnaire and rabies virus neutralising antibody (RVNA) measurement. The questionnaire was designed to assess all relevant factors of shelter management, which could impact the rabies vaccine antibody response. Thirteen participating shelters were classified into 4 groups, namely group A (best), B (good), C (fair), and D (require improvement). Sera were collected from randomly selected dogs (n = 113) within 4 weeks after rabies re-vaccination from a representative shelter of group B, C and D. Sample from group A was not included in the study due to time limitation. Both the number of dogs with acceptable response (RVNA ≥ 0.5 IU/ml) and the RVNA titres were significantly higher in group B than group C and D. Our results indicate that the quality of shelter management could affect rabies immune status.

Safety and immunogenicity of three dose levels of an investigational, highly purified Vero cell rabies vaccine: A randomized, controlled, observer-blinded, Phase II study with a simulated post-exposure regimen in healthy adults.

A serum-free, highly purified rabies vaccine produced in Vero cells is under development. The initial formulation, PVRV-NG, was evaluated in five Phase II studies and subsequently reformulated (PVRV-NG2). This multicenter, observer-blinded Phase II study investigated the safety and immune response of three different doses (antigen content) of PVRV-NG2 versus a licensed human diploid cell rabies vaccine (HDCV; Imovax rabies®). Healthy adults (N = 320) were randomized to receive PVRV-NG2 (low, medium, or high dose), PVRV-NG, or HDCV (2:2:2:1:1 ratio), according to a five-dose Essen simulated post-exposure regimen (Days [D] 0, 3, 7, 14, and 28). All participants received human rabies immunoglobulin intramuscularly on D0. Immunogenicity was assessed at D0, 14, 28, 42, and 6 months after the final injection using the rapid fluorescent focus inhibition test. Seroconversion rates were calculated as the percentage of participants achieving rabies virus neutralizing antibody titers ≥0.5 IU/mL. All analyses were descriptive. At each timepoint, geometric mean titers (GMTs) increased with antigen content (measured using an enzyme-linked immunosorbent assay). High-dose PVRV-NG2 GMTs were the highest at all timepoints, medium-dose PVRV-NG2 GMTs were similar to those with HDCV, and low-dose PVRV-NG2 GMTs were similar to PVRV-NG. The safety profile of PVRV-NG2 was comparable to PVRV-NG; however, fewer injection site reactions were reported with PVRV-NG2 or PVRV-NG (range 36.7-47.5%) than with HDCV (61.5%). This study demonstrated a dose-effect of antigen content at all timepoints. As post-exposure prophylaxis, the safety and immunogenicity profiles of the high-dose PVRV-NG2 group compared favorably with HDCV. Clinicaltrials.gov number: NCT03145766.

A novel mRNA rabies vaccine as a promising candidate for rabies post-exposure prophylaxis protects animals from different rabies viruses.

Rabies, caused by the rabies virus (RABV), is the most fatal zoonotic disease. It is a neglected tropical disease which remains a major public health problem, causing approximately 59,000 deaths worldwide annually. Despite the existence of effective vaccines, the high incidence of human rabies is mainly linked to tedious vaccine immunisation procedures and the overall high cost of post-exposure prophylaxis. Therefore, it is necessary to develop an effective vaccine that has a simple procedure and is affordable to prevent rabies infection in humans. RABV belongs to the genus Lyssavirus and family Rhabdoviridae. Previous phylogenetic analyses have identified seven major clades of RABV in China (China I-VII), confirmed by analysing nucleotide sequences from both the G and N proteins. This study evaluated the immunogenicity and protective capacity of SYS6008, an mRNA rabies vaccine expressing rabies virus glycoprotein, in mice and cynomolgus macaques. We demonstrated that SYS6008 induced sufficient levels of rabies neutralising antibody (RVNA) in mice. In addition, SYS6008 elicited strong and durable RVNA responses in vaccinated cynomolgus macaques. In the pre-exposure prophylaxis murine model, one or two injections of SYS6008 at 1/10 or 1/30 of dosage provided protection against a challenge with a 30-fold LD50 of rabies virus (China I and II clades). We also demonstrated that in the post-exposure prophylaxis murine model, which was exposed to lethal rabies virus (China I-VII clades) before vaccination, one or two injections of SYS6008 at both 1/10 and 1/30 dosages provided better protection against rabies virus challenge than the immunization by five injections of commercial vaccines at the same dosage. In addition, we proved that SYS6008-induced RVNAs could neutralise RABV from the China I-VII clades. Finally, 1/10 of the dosage of SYS6008 was able to stimulate significant RABV-G specificity in the T cell response. Furthermore, we found that SYS6008 induced high cellular immunity, including RABV-G-specific T cell responses and memory B cells. Our results imply that the SYS6008 rabies vaccine, with a much simpler vaccination procedure, better immunogenicity, and enhanced protective capacity, could be a candidate vaccine for post-exposure prophylaxis of rabies infections.

An mRNA vaccine against rabies provides strong and durable protection in mice.

Introduction: Rabies is a serious public health problem worldwide for which an effective treatment method is lacking but can be prevented by vaccines. Current vaccines are produced in cell or egg cultures, which are both costly and time consuming. Methods: Here, a non-replicating mRNA vaccine (RV021) encoding the rabies virus glycoprotein was developed in vitro, and its immunogenicity and protective efficacy against live virus was evaluated in mice. Results: A two-dose vaccination with 1 µg of RV021 at 7-day intervals induced a protective level of neutralizing antibody that was maintained for at least 260 days. RV021 induced a robust cellular immune response that was significantly superior to that of an inactivated vaccine. Two doses of 1 µg RV021 provided full protection against challenge with CVS of 30~60-fold lethal dose, 50%. Vaccine potency testing (according to the National Institutes of Health) in vivo revealed that the potency of RV021 at 15 µg/dose was 7.5 IU/dose, which is substantially higher than the standard for lot release of rabies vaccines for current human use. Conclusion: The mRNA vaccine RV021 induces a strong protective immune response in mice, providing a new and promising strategy for human rabies prevention and control.

Potential option for rabies post-exposure prophylaxis: New vaccine with PIKA adjuvant against diverse Chinese rabies strains.

Rabies is a fatal zoonotic disease caused by the rabies virus. Despite existing vaccines, failures still persist. Complete protection relies on improving vaccination for delayed antibody response and weak cellular immunity. A more effective and secure vaccine is necessary for rabies prevention. For this purpose, we employed the use of PIKA adjuvant, a stabilized double-stranded RNA that interacts with TLR3, as an enhancer for the rabies immunization. Testing on mice infected with seven rabies strains prevalent in China showed over 80% protective efficacy without immunoglobulin. In contrast, the PIKA rabies vaccine exhibited a more significant enhancement in neutralizing antibody levels just 5 days post-vaccination, surpassing the immune response induced by licensed rabies vaccines. Furthermore, the administration of the PIKA rabies vaccine resulted in a significant augmentation in the population of T cells that produce IFN-γ in response to the antigen. Additionally, elevated levels of IL-1ß, IL-6, CCL-2, and TNF-α were observed at the injection site. Furthermore, an increase in the levels of chemotactic proteins and pro-inflammatory molecules in the serum was observed following administration of the PIKA rabies vaccine. Confirmation of the mechanism of action of PIKA was further established by testing it on TLR3-knockout mice, proving that its adjuvant function is dependent on the TLR3 pathway. Taken together, these results indicate that the PIKA vaccine for rabies shows potential as a highly efficacious approach, resulting in a significant enhancement of the efficacy of rabies vaccines.

A Pediatric Level III Trauma Center Experience With Dog Bite Injuries.

Dog bite injuries often present to Emergency Departments (ED), and between 2001 and 2003, approximately 4.5 million adults and children were injured. Injuries may range from puncture wounds to deep tissue lacerations or avulsions. Deaths have been described. Our objective was to describe dog bite injuries, the overall location of injuries, and need for vaccination among children who presented to a Pediatric ED designated as a level III trauma center with a robust facial surgical infrastructure. This was a 6-year retrospective study. Charts were identified by International Classification of Diseases, Tenth Revision (ICD-10) codes for lacerations or injuries secondary to animal bites and accessing the hospital's trauma database. Variables abstracted were age, sex, type of injury, location, need for antibiotics, immunization states and requirement of tetanus or rabies vaccine, disposition from ED to the operating room, home, or any in-patient unit. We excluded children older than 17 years of age and children who had a post-bite injury infection or injury not initially managed in our facility or medical system. The final cohort consisted of 152 children. The median age was 52 months and age ranged from 2 to 215 months. Children with a single bite injury were older when compared with those with numerous injuries, 81 and 62 months of age, respectively. Among young children, 75% of injuries occurred above the neck and 15.1% were managed in the operating room. Twenty-four percent of children required either a tetanus or rabies vaccination. Most dog bite injuries occurred to facial structures. Comprehensive care of dog victims included awareness of both dog and injured child vaccination status.

Immune Response of Inactivated Rabies Vaccine Inoculated via Intraperitoneal, Intramuscular, Subcutaneous and Needle-Free Injection Technology-Based Intradermal Routes in Mice.

Inoculation routes may significantly affect vaccine performance due to the local microenvironment, antigen localization and presentation, and, therefore, final immune responses. In this study, we conducted a head-to-head comparison of immune response and safety of inactivated rabies vaccine inoculated via intraperitoneal (IP), intramuscular (IM), subcutaneous (SC) and needle-free injection technology-based intradermal (ID) routes in ICR mice. Immune response was assessed in terms of antigen-specific antibodies, antibody subtypes and neutralizing antibodies for up to 28 weeks. A live rabies virus challenge was also carried out to evaluate vaccine potency. The dynamics of inflammatory cell infiltration at the skin and muscle levels were determined via histopathological examination. The kinetics and distribution of a model antigen were also determined by using in vivo fluorescence imaging. Evidence is presented that the vaccine inoculated via the ID route resulted in the highest antigen-specific antibody and neutralizing antibody titers among all administration routes, while IP and IM routes were comparable, followed by the SC route. Antibody subtype analysis shows that the IP route elicited a Th1-biased immune response, while SC and IM administration elicited a prominent Th2-type immune response. Unexpectedly, the ID route leads to a balanced Th1 and Th2 immune response. In addition, the ID route conferred effective protection against lethal challenge with 40 LD50 of the rabies CVS strain, which was followed by IP and IM routes. Moreover, a one-third dose of the vaccine inoculated via the ID route provided comparable or higher efficacy to a full dose of the vaccine via the other three routes. The superior performance of ID inoculation over other routes is related to longer local retention at injection sites and higher lymphatic drainage. Histopathology examination reveals a transient inflammatory cell infiltration at ID and IM injection sites which peaked at 48 h and 24 h, respectively, after immunization, with all side effects disappearing within one week. These results suggest that needle-free injection technology-based ID inoculation is a promising strategy for rabies vaccination in regard to safety and efficacy.

A Randomized, Double-Blind, Controlled Phase III Clinical Trial to Evaluate the Immunogenicity and Safety of a Lyophilized Human Rabies Vaccine (Vero Cells) in Healthy Participants Aged 10-60 Years Following Essen and Zagreb Vaccination Procedures.

OBJECTIVE: In this paper, we aim to show that the immunogenicity of the lyophilized human rabies vaccine (Vero cells) (investigational vaccine) developed by Dalian Aleph Biomedical Co., Ltd. in healthy participants aged 10-60 years old is non-inferior to the lyophilized PVRV (positive control) manufactured by Liaoning Chengda Biotechnology Co., Ltd. (Shenyang, China), and that its safety is clinically acceptable. METHOD: A total of 2776 participants were enrolled in this study and divided into four groups: a five-dose test group, a five-dose control group, a four-dose test group, and a four-dose control group. The patients in the four-dose groups (Zagreb) were vaccinated on Days 0 (two doses), 7 (one dose), and 21 (one dose), and those in the five-dose groups (Essen) were vaccinated on Days 0, 3, 7, 14, and 28 (one dose each). The rabies-virus-neutralizing antibody assay with the RFFIT was used to assess the immunogenicity, and the adverse events (AEs) and serious adverse events (SAEs) were identified and collated. RESULTS: The positive seroconversion rate was up to 100% on Days 14 and 35/42 after vaccination following any procedures in pre-immunization antibody-negative participants, and the positive seroconversion rate and geometric mean concentration (GMC) of the test groups (Zagreb and Essen vaccination procedures) was not inferior to that of the control groups. On Day 7 after vaccination, the immunogenicity of the Zagreb procedure with two doses of the vaccine on Day 0 was superior to the Essen procedure with one dose of vaccine, that is, the former had a higher seroconversion rate and RVNA titer. The non-inferiority criterion of immunogenicity was met for the whole population, the population aged 10-18 years and ≥18 years, and the pre-immunization antibody-positive population. The incidences of all AEs, solicited AEs, and unsolicited AEs in both groups were not statistically significant, and no vaccination-related SAEs were observed. CONCLUSION: The investigated vaccine is safe, its immunogenicity is non-inferior to that of the control vaccine, and the efficacy of the Zagreb procedure is superior to that of the Essen procedure 7 days after the first dose.

Inventory management practices: implications on the pharmaceuticals expenditure of rabies vaccine in public health facilities, Namibia.

BACKGROUND: To achieve well-regulated distribution, storage, and utilization of the rabies vaccine, health facilities should adhere to standard operating procedures. In Namibia, information on inventory management, utilization, monitoring, and reporting of rabies vaccine adherence to standard operating procedures in public healthcare facilities is insufficient. The aim of this study was to assess adherence to rabies vaccine standard operating procedures and inventory management and to compare rabies vaccine expenditure to the number of patients who received rabies vaccination at the Ministry of Health and Social Services' public healthcare facilities from 2018 to 2020. METHODS: A cross-sectional, web-based questionnaire consisting of closed-ended questions was sent to 147 pharmacy staff and warehouse managers working in the 14 regions of Namibia during the period of May 1, 2021, to June 2, 2021. The overall expenditure and the total number of patients vaccinated from 2018 to 2020 were obtained from national-level logistic and vaccination program coordinators. Data were coded and transcribed into Microsoft® Excel® 2013 and analyzed using SPSS® version 27. RESULTS: One hundred and thirty-three completed questionnaires were received from sixty-nine public health centers and hospitals. The group of respondents consisted of pharmacist assistants (50%), pharmacy technicians (12%), pharmacists (36.8%), senior pharmacists (0.8%), and chief pharmacists (1.5%). Overall, adherence to standard operating procedures was poor (27.1%). Rabies vaccine distributed to public health facilities from 2018 to 2020 was worth N$75,381,419.91 (~ US$4,074,671.46) and was expected to vaccinate 87,269 patients; however, only 95 cases of both rabies and rabid dog-bite patients were reported. The major inventory management challenges for public healthcare facilities include an inadequate number of pharmacy staff, poor adherence to standardized pharmaceutical warehousing, lack of regular supervision, and inadequate staff training. CONCLUSION: Inventory management practices in public healthcare facilities were not in compliance with standard operating procedures. There is a significant discrepancy between rabies vaccine expenditure and the number of patients that were vaccinated. Therefore, there is a need for adequate staff training on inventory management and regular facility supervision to enforce optimal rabies vaccine inventory management practices.

Active safety surveillance of rabies monoclonal antibody and rabies vaccine in patients with category III potential rabies exposure.

Background: A vero cell-based inactivated Rabies Vaccine (Rabivax-S) and Rabies Human Monoclonal Antibody (Rabishield) have been approved since 2016. A post-marketing surveillance was conducted in India from 2020 to 2021 to gather real world safety data on Rabivax-S and Rabishield. Methods: This was non-interventional active surveillance in patients with category III potential rabies exposure who were administered a post-exposure prophylaxis (PEP) regimen (Rabishield and Rabivax-S) by their healthcare providers (HCPs) as per the dosages and regimens mentioned in the package insert approved by the Indian regulators. The approved schedule for PEP was local infiltration of Rabishield on Day 0 and five doses of Rabivax-S on Day 0, 3, 7, 14, and 28 (Intramuscular route, IM) or four doses of Rabivax-S on Day 0, 3, 7, and 28 (Intradermal route, ID). The primary objective of this surveillance was to generate real-world evidence on the safety and tolerability of Rabishield and Rabivax-S. All patients enrolled in the surveillance were required to report any adverse events (AEs) occurring up to Day 31 after initiation of PEP (administration of Rabishield and the first dose of Rabivax-S) to their HCP. Findings: A total of 1000 patients with category III potential rabies exposure were enrolled across India. 991 patients received the PEP regimen with IM Rabivax-S while 9 received a PEP regimen with the ID regimen. While 32% of the patients were <12 years of age, 11.8% were ≥12 to <18 years of age and 56.2% were ≥18 years of age. The entire PEP regimen was completed by 97.3% of the enrolled patients. A total of 69 AEs were reported in 64 patients. Out of these, 49 AEs in 47 patients were assessed as causally related to the study products (26 with Rabishield and 23 with Rabivax-S). The majority of the AEs were mild and all recovered without any sequelae. One serious adverse event (SAE) of fracture of the hand was reported which was not related to either Rabishield or Rabivax-S. No case of rabies was reported. Interpretation: Rabishield and Rabivax-S have an excellent safety profile and are well tolerated. No participant developed rabies during 31 day follow up. Funding: The PMS was funded by Serum institute of India Private Limited which is the manufacturer of the study products.

Immune-adjuvant effect of vitamin A and probiotics supplementation on humoral response to cell culture rabies vaccine in rabbits.

This study was carried out to evaluate the effects of vitamin A (Vit A) and probiotic co-supplementation with rabies vaccine on humoral immune response in New Zealand white (NZW) rabbits. For this experiment, 54 rabbits were randomized into six experimental and three control groups. Mixed cultures of commercial probiotics supplements and a dose of Vit A were administered to each animal. Results were compared with the control group fed with only basal diet. Animals in different treatment groups showed significantly higher sero-conversions against rabies vaccine. There was a significant increase (p < 0.001) in the titers of rabies antibodies in all treatment groups on 14th and 35th days than control C3 group. Both commercial probiotics irrespective of brand increase the humoral immune response of rabbits against rabies vaccine. The mean titer values of all groups G1-G6 and sub-controls (C1, C2) were generally above 3.6 EU/ml on day 14th and between 3.7 and 3.9 EU/ml, showing highest sero-conversion on 35th day than mean titer of C3 control = 3.091 and 3.505 EU/ml respectively on both days. The maximum titer values were obtained with the addition of organic carrots to the daily diet. These results suggest that simple dietary interventions using probiotics and Vit A in natural form may enhance the efficacy of rabies vaccine in the host. These cost-effective strategies can be applied for getting higher yields of polyclonal antibody production in animal models, thus providing promising means of improving the final product yield and can be adopted easily by the manufacturers.

Short-Chain Fatty Acids Alleviate Vancomycin-Caused Humoral Immunity Attenuation in Rabies-Vaccinated Mice by Promoting the Generation of Plasma Cells via Akt-mTOR Pathway.

Mounting evidence suggests that gut microbial composition and its metabolites, including short-chain fatty acids (SCFAs), have beneficial effects in regulating host immunogenicity to vaccines. However, it remains unknown whether and how SCFAs improve the immunogenicity of the rabies vaccine. In this study, we investigated the effect of SCFAs on the immune response to rabies vaccine in vancomycin (Vanco)-treated mice and found that oral gavage with butyrate-producing bacteria (C. butyricum) and butyrate supplementation elevated RABV-specific IgM, IgG, and virus-neutralizing antibodies (VNAs) in Vanco-treated mice. Supplementation with butyrate expanded antigen-specific CD4+ T cells and IFN-γ-secreting cells, augmented germinal center (GC) B cell recruitment, promoted plasma cells (PCs) and RABV-specific antibody-secreting cells (ASCs) generation in Vanco-treated mice. Mechanistically, butyrate enhanced mitochondrial function and activated the Akt-mTOR pathway in primary B cells isolated from Vanco-treated mice, ultimately promoting B lymphocyte-induced maturation protein-1 (Blimp-1) expression and CD138+ PCs generation. These results highlight the important role of butyrate in alleviating Vanco-caused humoral immunity attenuation in rabies-vaccinated mice and maintaining host immune homeostasis. IMPORTANCE The gut microbiome plays many crucial roles in the maintenance of immune homeostasis. Alteration of the gut microbiome and metabolites has been shown to impact vaccine efficacy. SCFAs can act as an energy source for B-cells, thereby promoting both mucosal and systemic immunity in the host by inhibiting HDACs and activation of GPR receptors. This study investigates the impact of orally administered butyrate, an SCFA, on the immunogenicity of rabies vaccines in Vanco-treated mice. The results showed that butyrate ameliorated humoral immunity by facilitating the generation of plasma cells via the Akt-mTOR in Vanco-treated mice. These findings unveil the impact of SCFAs on the immune response of the rabies vaccine and confirm the crucial role of butyrate in regulating immunogenicity to rabies vaccines in antibiotic-treated mice. This study provides a fresh insight into the relationship of microbial metabolites and rabies vaccination.