Inactivated rabies vaccines: Standardization of an in vitro assay for residual viable virus detection

Rabies Vaccine for Prophylaxis and Treatment of Rabies: A Narrative Review

Rabies, a millennia-old viral infection transmitted through animal bites, poses a lethal threat to humans, with a historic fatality rate of 100% if left untreated. Louis Pasteur's introduction of the rabies vaccine in 1885 marked a turning point in the battle against rabies, preventing numerous cases. The purpose of this paper is to review the historical development, current challenges, and future prospects of rabies vaccination and treatment, with emphasis on the importance of continued research and collaborative efforts in the quest to eradicate this deadly infection. Historical vaccine development progressed from inactivated to live-attenuated forms, with modern recombinant techniques showing promise. The preventive measures at present primarily involve vaccination, but challenges persist, such as differing safety profiles and immunogenicity among vaccine types. Pre-exposure prophylaxis with a three-dose vaccine series is crucial, especially in high-risk scenarios. Post-exposure prophylaxis combines human rabies immunoglobulin and inactivated rabies virus vaccine. The quest for the next generation of vaccines explores genetically modified and viral vector-based approaches; emerging treatments include gene therapy, virus-like particles, and monoclonal antibodies, offering hope for improved outcomes. Economic barriers to post-exposure prophylaxis, limited education, and awareness challenge rabies control. Cost-effective solutions and comprehensive awareness campaigns are vital for the successful eradication of rabies. More research and collaborative endeavors remain pivotal in the ongoing journey to eradicate rabies, one of the deadliest infectious diseases known to humans, if not met with prophylactic measures.

Immunogenicity and protective efficacy of a co-formulated two-in-one inactivated whole virus particle COVID-19/influenza vaccine

Due to the synchronous circulation of seasonal influenza viruses and severe acute respiratory coronavirus 2 (SARS-CoV-2) which causes coronavirus disease 2019 (COVID-19), there is need for routine vaccination for both COVID-19 and influenza to reduce disease severity. Here, we prepared individual WPVs composed of formalin-inactivated SARS-CoV-2 WK 521 (Ancestral strain; Co WPV) or influenza virus [A/California/07/2009 (X-179A) (H1N1) pdm; Flu WPV] to produce a two-in-one Co/Flu WPV. Serum analysis from vaccinated mice revealed that a single dose of Co/Flu WPV induced antigen-specific neutralizing antibodies against both viruses, similar to those induced by either type of WPV alone. Following infection with either virus, mice vaccinated with Co/Flu WPV showed no weight loss, reduced pneumonia and viral titers in the lung, and lower gene expression of proinflammatory cytokines, as observed with individual WPV-vaccinated. Furthermore, a pentavalent vaccine (Co/qFlu WPV) comprising of Co WPV and quadrivalent influenza vaccine (qFlu WPV) was immunogenic and protected animals from severe COVID-19. These results suggest that a single dose of the two-in-one WPV provides efficient protection against SARS-CoV-2 and influenza virus infections with no evidence of vaccine interference in mice. We propose that concomitant vaccination with the two-in-one WPV can be useful for controlling both diseases.

Exigency of Plant-Based Vaccine against COVID-19 Emergence as Pandemic Preparedness

After two years since the declaration of COVID-19 as a pandemic by the World Health Organization (WHO), more than six million deaths have occurred due to SARS-CoV-2, leading to an unprecedented disruption of the global economy. Fortunately, within a year, a wide range of vaccines, including pathogen-based inactivated and live-attenuated vaccines, replicating and non-replicating vector-based vaccines, nucleic acid (DNA and mRNA)-based vaccines, and protein-based subunit and virus-like particle (VLP)-based vaccines, have been developed to mitigate the severe impacts of the COVID-19 pandemic. These vaccines have proven highly effective in reducing the severity of illness and preventing deaths. However, the availability and supply of COVID-19 vaccines have become an issue due to the prioritization of vaccine distribution in most countries. Additionally, as the virus continues to mutate and spread, questions have arisen regarding the effectiveness of vaccines against new strains of SARS-CoV-2 that can evade host immunity. The urgent need for booster doses to enhance immunity has been recognized. The scarcity of "safe and effective" vaccines has exacerbated global inequalities in terms of vaccine coverage. The development of COVID-19 vaccines has fallen short of the expectations set forth in 2020 and 2021. Furthermore, the equitable distribution of vaccines at the global and national levels remains a challenge, particularly in developing countries. In such circumstances, the exigency of plant virus-based vaccines has become apparent as a means to overcome supply shortages through fast manufacturing processes and to enable quick and convenient distribution to millions of people without the reliance on a cold chain system. Moreover, plant virus-based vaccines have demonstrated both safety and efficacy in eliciting robust cellular immunogenicity against COVID-19 pathogens. This review aims to shed light on the advantages and disadvantages of different types of vaccines developed against SARS-CoV-2 and provide an update on the current status of plant-based vaccines in the fight against the COVID-19 pandemic.

Research trends in rabies vaccine in the last three decades: a bibliometric analysis of global perspective

INTRODUCTION

Rabies is an infectious zoonotic viral disease which mainly occurs in Africa and Asia. Dogs are predominantly responsible for rabies transmission contributing up to 99% of all human rabies cases. Rabies is a vaccine preventable disease in both animals and humans.

OBJECTIVE

This study aimed to quantify and characterize the scientific literature and identify the top most cited studies in rabies vaccine research (RVR) from 1991 to 2020.

METHODS

The data used in this study were downloaded from Web of Science Core Collection (WoSCC), Science Citation Index-Expanded (SCI-E) database. Network visualization analysis was performed using VOSviewer software.

RESULTS

A total of 1,042 papers (article: n = 986, 94.6%, review: n = 56, 5.4%) were included in this study. These have been cited 17,390 times with an average citation per paper was 16.69 times. The most frequent publication year was 2019 (n = 75, 7.2%). More than 55% studies were published from the United State of America (USA) (n = 380, 36.5%), France (n = 128, 12.3%), and China (n = 97, 9.3%). The most studied Web of Science (WoS) category was immunology (n = 344, 33%). The most prolific author in RVR was Rupprecht CE (n = 55, 5.3%). 'Vaccine' was the leading journal (n = 218, 20.9%). Rabies was the most widely used keyword.

CONCLUSION

Abundant literature has been published on RVR in developed countries. This study might provide a reference to understand the current and future research trends in RVR. In developing countries research collaboration and co-operation among institutes and researchers needs to be strengthened with developed countries.

Development of an assay for detecting the residual viable virus in inactivated rabies vaccine by enzyme-linked immunosorbent assay

Rabies is a zoonotic disease that can be prevented by vaccination. The confirmation of rabies virus inactivation is a critical step during the vaccine quality test; however, the current protocol conducted in Japan requires a large number of mice. The development and introduction of animal-free alternative assays are essential from the perspective of the 3Rs (reduction, refinement, and replacement) of animal testing. Here, we propose a novel inactivation assay for confirming the complete inactivation of the viable rabies virus using cultured Neuro-2a cells and an enzyme-linked immunosorbent assay (ELISA). The detection ability of ELISA was similar to that of a direct immunofluorescence assay, with the detection limit of ELISA being as low as 0.014 focus forming units/test. These results suggest that the assay could be used as a viral inactivation test. In comparison with a traditional in vivo assay, this assay has a higher detection ability, an objective interpretation, and would shorten the test duration from 25 days to 8 days.