Post-exposure #prophylaxis regimen of #rabies monoclonal #antibody and #vaccine in category 3 potential exposure patients ...

 

Summary

Background

Rabies is almost invariably fatal. A rabies monoclonal antibody (RmAb) was approved in India in 2016 for passive prophylaxis. This post-marketing study aimed to evaluate the long-term safety, immunogenicity, and efficacy of a post-exposure prophylaxis (PEP) regimen containing RmAb.

Methods

This phase 4, open-label, randomised, active-controlled study was conducted at 15 tertiary care hospitals in India. Patients aged 2 years or older with WHO category 3 rabies exposure by a suspected rabid animal were eligible if the exposure occurred less than 72 h before enrolment, or less than 24 h before enrolment for exposures to the face, neck, hand, or fingers. Participants were randomly assigned (3:1) to receive either RmAb (Rabishield; Serum Institute of India, Pune, India) plus a purified Vero cell rabies vaccine (PVRV; Rabivax-S) or equine rabies immunoglobulin (ERIG; Equirab) plus PVRV as PEP. In each treatment group, patients were further randomly assigned (1:1) to receive PVRV either intradermally or intramuscularly. Study group allocation was done using a permuted block design with random block sizes of eight. A central randomisation list was generated before the study start and randomisation was performed with an interactive web response system. Participants and site personnel were not masked to group assignment. RmAb (3·33 IU/kg) and ERIG (40 IU/kg) were infiltrated into and around the wounds only on day 0 as per WHO 2018 recommendations. PVRV was administered 1·0 mL intramuscularly (days 0, 3, 7, 14, and 28) or 0·1 mL plus 0·1 mL intradermally (days 0, 3, 7, and 28). The primary outcome was treatment-related serious adverse events up to 365 days after immunisation, analysed in the safety analysis set (all participants who received at least one dose of vaccine with treatment). Geometric mean concentrations of rabies virus neutralising antibody were measured in a subset of patients. This study is registered with Clinical Trial Registry–India (CTRI/2019/06/019622) and is completed.

Findings

4059 participants were enrolled between Aug 21, 2019, and March 31, 2022, and randomly assigned. A total of 3994 participants (3001 male, 993 female) were treated (2996 RmAb plus PVRV, 998 ERIG plus PVRV), of which 3622 (90·7%) participants completed the 1-year follow-up. 11 adverse events were considered causally related to RmAb plus PVRV and 17 were considered causally related to the ERIG plus PVRV regimen. Most adverse events were mild and transient. Seven serious adverse events occurred in the RmAb group and all were causally unrelated. One causally related serious adverse event was reported in the ERIG group. On day 14, the geometric mean concentrations increased to 16·05 IU/mL (95% CI 13·25–19·44) in the RmAb group and 13·48 IU/mL (9·51–19·11) in the ERIG group (point estimate 1·19 [95% CI 0·82–1·72]). No patient developed rabies during the 1-year follow-up period.

Interpretation

RmAb was safe and well tolerated and showed protective efficacy against rabies. A PEP regimen containing RmAb plus PVRV was immunogenic with long-term persistence of immune response.

Funding

Serum Institute of India.

Source: Lancet, https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(25)00735-4/abstract?rss=yes

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Broad geographical #circulation of a novel #vesiculovirus in #bats in the #Mediterranean region

Abstract

Bats are the natural reservoirs for a variety of emerging and re-emerging viruses. Among them, rabies virus (genus Lyssavirus, family Rhabdoviridae) is one of the first and most emblematic described in these animals. Since its first description, several new bat lyssaviruses have been regularly identified. In addition to lyssaviruses, other bat rhabdoviruses have also been discovered, including members of the genera Vesiculovirus, Ledantevirus and, more recently, Alphanemrhavirus and Tupavirus. However, the family Rhabdoviridae is one of the most abundant and diverse viral families, with 434 officially recognized species, divided into 5 subfamilies and 56 different genera. The number of rhabdoviruses associated with bats is therefore probably higher than that currently available. In this study, we first developed and validated a combined nested RT-qPCR technique (pan-rhabdo RT-nqPCR) dedicated to the broad detection of animal rhabdoviruses. After validation, this technique was used for a large retrospective screening of archival bat samples (n = 1962), including blood (n = 816), brain (n = 723) and oral swab (n = 423). These samples were collected from various bat species over a 12-year period (2007–2019) in 9 different countries in Europe and Africa. A total of 23 samples (1.2%) from bat species Miniopterus schreibersii, Rhinolophus euryale and Rhinolophus ferrumequinum tested positive for rhabdovirus infection, including 17 (2.1%) blood and 6 (1.4%) oral swab samples, all collected from bats originating from the Mediterranean region. Complete virus genome sequences were obtained by next-generation sequencing for most of the positive samples. Molecular and phylogenetic analysis of these sequences demonstrated that these virus isolates, named Mediterranean bat virus (MBV), were closely related and represented a new species, Mediterranean vesiculovirus, within the Vesiculovirus genus. MBV was more specifically related to other bat vesiculoviruses previously described from China and North America, together clustering into a distinct group of bat viruses within this genus. Interestingly, our results suggest that MBV is widespread, at least in the western part of the Mediterranean region, where it circulates in the blood of several bat species. These results expand the host range and viral diversity of bat vesiculoviruses, and pave the way for further studies to determine the transmission route and dissemination dynamics of these viruses in bat colonies, as well as to assess their potential threat to public health.

Author summary

Bats are the natural hosts for a wide variety of viruses, particularly those belonging to the family Rhabdoviridae, which include the lyssaviruses, the etiological agents of rabies. This viral family is one of the most abundant and diverse, with 434 officially recognized species. However, the current diversity of these viruses in bats remains poorly understood. To address this, we developed a new method for detecting rhabdoviruses in bat samples collected over a period of 12 years in several European and African countries. From nearly 2,000 samples, we discovered a new rhabdovirus, which was named Mediterranean bat virus (MBV). MBV has been detected in the blood and oral swabs of specific bat species (Rhinolophus sp. and Miniopterus schreibersii) living on both sides of the Mediterranean region. Based on phylogenetic analysis, we determined that MBV represented a unique group within the genus Vesiculovirus, but still related to other bat vesiculoviruses discovered in China and North America. These results expand the host range and viral diversity of bat rhabdoviruses, and pave the way for further studies to determine the transmission route and dissemination dynamics of these viruses in bat colonies, as well as to assess their potential threat to public health.

Source: PLoS Neglected Tropical Diseases, https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0013172

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Genomic and #Clinical #Analysis of a #Fatal Human #Lyssavirus irkut Case: Evidence for a Natural Focus in the Russian Far East

Abstract

In this report, we document and analyze a case in which the Irkut virus (IRKV) (Mononegavirales: Rhabdoviridae) caused a fatal human case following a bat bite in June 2021. Unfortunately, the available data did not permit a detailed taxonomic classification of the carrier bat (Chiroptera). The event occurred in the southwestern part of the Sikhote-Alin mountain region (Russian Far East) covered by the Ussuri taiga forest. The symptoms of the illness began with the following: fever; pronounced psychomotor and motor agitation; tremor of the lower jaw and tongue; aphasia; dyslexia; and dysphagia. These rapidly developed, leading to a severe and fatal encephalitis. The patient was not vaccinated for rabies and did not receive rabies immunoglobulin. Using brain sections prepared from the deceased, molecular diagnostics were performed: immunofluorescence (polyclonal anti-rabies immunoglobulin) indicating the presence of the lyssavirus antigen; and RT-PCR indicating traces of viral RNA. Sectional material (brain) was used for whole-genome sequencing, resulting in a near-complete sequence of the lyssavirus genome. The obtained genomic sequence was identified as the Irkut virus. A comparative analysis of the new sequence and other currently available IRKV sequences (NCBI) revealed differences. Specifically, amino acid differences between antigenic sites in the isolate and those of the rabies vaccine strain used regionally were noted. The patient history and subsequent analysis confirm human IRKV infection following bat contact. Like other fatal cases of IRKV infection described earlier, this case occurred in the southern part of the Russian Far East. Two have occurred in the southwestern part of the Sikhote-Alin mountain region. This indicates the possible existence of an active, natural viral focus.

Source: Viruses, https://www.mdpi.com/1999-4915/17/6/769

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