The H9N2 subtype of avian influenza virus (AIV) emerges as a significant member of the influenza A virus family. However, the varying degrees of epidemiological dominance among different lineages or clades of H9N2 AIVs have not been fully clarified. The matrix protein M1, a key structural component of the virion, plays a crucial role in maintaining the viral structure and lifecycle. To elucidate the intrinsic relationship between the genetic patterns of M1 and the adaptive dynamics of H9N2 AIVs, this study focused on the five major evolutionary patterns of M1 and conducted in vitro and in vivo investigations from the perspectives of vRNP release after viral uncoating, polymerase activity, mRNA and vRNA levels, the nuclear export of vRNPs, plasma membrane-binding capacity, proliferation capacity, growth competitiveness, and transmission potential. The results revealed a strong correlation between the epidemiological dominance of H9N2 AIVs and the specific patterns of M1, with M1P5 standing out as particularly significant. This finding highlights the pivotal influence of the M1 gene patterns on the replication and transmission dynamics of H9N2 AIVs, thereby offering valuable insights into the mechanisms driving differences in adaptive evolution and shifts in epidemiological dominance within the H9N2 AIV population.

Rabies is a zoonotic disease caused by the rabies virus (RABV). RABV infections cause severe destruction to the central nervous system with fatal consequences, which has prompted global efforts to develop a highly effective and safe vaccine. Currently, the most widely used vaccines are inactivated vaccines, which need multiple injected doses for either pre-exposure prophylaxis or post-exposure immunization. This adds a lot of unnecessary trouble and labor costs. mRNA vaccines represent a promising platform against emerging and re-emerging infectious diseases, because they can induce high levels of virus-neutralizing antibodies (VNAs). In this study, we obtained a highly effective expression of rabies glycoprotein mRNA molecule by the optimized mRNA preparation procedure and encapsulated with lipid nanoparticles (LNP), termed mRNA-LNP vaccine. A single dose of the mRNA-LNP was highly immunogenic and induced a rapid protective antibody response in mice. Antibodies play a pivotal role in protecting against lethal RABV infections and eliminate the virus by blocking it from invading the CNS. One dose of the mRNA-LNP vaccine induced higher and more durable VNA titers in dogs and cats compared with the licensed inactivated vaccines, intriguingly, the antibody titers were higher in cats than in dogs. Furthermore, the immunogenicity of the freeze-dried vaccine was not significantly declined when compared with a freshly prepared vaccine, and it can be stored at -20℃ for 4 months. All the above results show that the mRNA-LNP vaccine is safe and effectively exhibited robust immune responses both for dogs and cats with a single-dose administration, which being promising to be a candidate vaccine against rabies.

Recently, Spencer et al. published their interesting article in Influenza and Other Respiratory Viruses providing evidence that there is no impact of diabetes status on immunogenicity of trivalent inactivated influenza vaccine in older adults. Although we agree with the conclusion, we suggest that the transportation condition of the serum samples should be added in the description of serological surveys of influenza in the future. Stability of specific influenza antibodies in sera samples stored in differing conditions should be considered.

In June 2021, Udom et al. published their article in Transboundary and Emerging Diseases performing a serological survey revealed evidence of anti-N-IgG antibodies suggesting SARS-CoV-2 exposure in both dogs and cats during the first and second coronavirus disease 2019 (COVID-19) outbreaks in Thailand. Seroprevalence studies have proven an important tool to monitor the progression of the COVID-19 pandemic. The duration of immunity of SARS-CoV-2 is crucial for the course of the pandemic and for this reason the monitoring of antibodies against SARS-CoV-2 is important. The serum samples from different periods and regions were valuable in terms of scientific significance for serological survey of SARS-CoV-2 and emerging infectious diseases. In order to preserve the remaining serum samples and ensure the stability of anti-virus antibodies in storage serum samples, we strongly suggest that standard serum banks should be established worldwide.

In contrast to dog-associated human rabies cases decline year by year due to the rabies vaccination coverage rates increase in China, ferret badger (FB, Melogale moschata)-associated human rabies cases emerged in the 1990s, and are now an increasingly recognized problem in southeast China. To investigate epidemiology, temporal evolution dynamics, transmission characterization, and pathogenicity of FB-associated rabies viruses (RABVs), from 2008 to 2018, we collected 3,622 FB brain samples in Jiangxi and Zhejiang Province, and detected 112 RABV isolates. Four FB-related lineages were identified by phylogenetic analysis (lineages A-D), the estimated Times to Most Recent Common Ancestor were 1941, 1990, 1937, and 1997 for lineages A-D, respectively. Furthermore, although no FB-associated human rabies case has been reported there apart from Wuyuan area, FB-RABV isolates are mainly distributed in Jiangxi Province. Pathogenicity of FB-RABVs was assessed using peripheral inoculation in mice and in beagles with masseter muscles, mortality-rates ranging from 20 to 100% in mice and 0 to 20% in beagles in the groups infected with the various isolates. Screening of sera from humans with FB bites and no post-exposure prophylaxis to rabies revealed that five of nine were positive for neutralizing antibodies of RABV. All the results above indicated that FB-RABV variants caused a lesser pathogenicity in mice, beagles, and even humans. Vaccination in mice suggests that inactivated vaccine or recombinant subunit vaccine products can be used to control FB-associated rabies, however, oral vaccines for stray dogs and wildlife need to be developed and licensed in China urgently.

The study aimed to determine the status of neutralizing antibodies and rabies virus infection in dogs at slaughterhouses in Hanoi city from 2015 to 2017. A total of 2,376 pairs of blood and brain samples were collected from dogs at 92 slaughterhouses (8 large slaughterhouses and 84 small slaughterhouses) in 6 districts in Hanoi. Of the 1,500 dog samples from the large slaughterhouses where imported dogs were slaughtered, no dog brain samples were infected with rabies virus and no blood samples were positive for rabies neutralizing antibodies. Meanwhile, 7/876 (0.8%) of dog brain samples from small slaughterhouses in which slaughtered local dogs were positive for rabies virus and 26.4% had neutralizing antibodies against rabies virus. Analysis of the genetic characteristics of these rabies viruses showed that they all had a common origin with the domestic strains circulating in Northern Vietnam. Research results suggested that there was a potential risk of rabies transmission to humans through dog slaughtering activities in Vietnam. Vaccination for dogs should be strengthened, strictly implemented and frequently monitored to reach the rate of herd vaccination coverage as WHO's recommendation. Dog trading and slaughtering activities should be strictly monitored to minimize the risk of rabies transmission to humans.

In May 2020, Deng et al. (2020) published their article providing the evidence that no SARS-CoV-2-specific antibodies were detected in 1,914 samples which excluded the possibility of 35 animal species as intermediate host for SARS-CoV-2 in Transboundary and Emerging Diseases. In order to ensure the stability of SARS-CoV-2-specific antibodies in storage serum samples, we strongly suggest that standard serum banks should be established.

In May 2020, Deng et al. (2020) published their article in Transboundary and Emerging Diseases providing evidence that no SARS-CoV-2-specific antibodies were detected in 1,914 samples which excluded the possibility of 35 animal species as intermediate host for SARS-CoV-2. In order to ensure the stability of SARS-CoV-2-specific antibodies in storaged serum samples, we strongly suggest that standard serum banks should be established.

We read with interest ‘Seroprevalence of Lyme borreliosis in Finland 50 years ago’ [[1]Cuellar J. Dub T. Sane J. Hytönen J. Seroprevalence of Lyme borreliosis in Finland 50 years ago.Clin Microbiol Infect. 2019 Oct 14; (S1198-743X(19)30530-0)Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar]. The authors studied the Lyme borreliosis (LB) seroprevalence in Finland in the 1960s and 1970s through evaluation of immunoglobulin G (IgG) against Borrelia burgdorferi in historical serum samples. Despite its scientific and comprehensive, we want to point out some technical issues that ought to be discussed. The key point of this study was the stability of IgG antibodies for B. burgdorferi in long-term-storage serum samples, which were collected from different regions in Finland between 1966 and 1972 [[2]Knekt P. Rissanen H. Jarvinen R. Heliövaara M. Cohort profile: the Finnish mobile clinic health surveys FMC, FMCF and MFS.Int J Epidemiol. 2017; 46: 1760e1Crossref Scopus (21) Google Scholar]. The serum samples were stored at −20°C for more than 50 years. According to the authors, ‘For serum quality check, the IgG antibody level in 41 randomly selected samples was measured using an in-house ELISA towards varicella zoster virus (VZV). All but three samples contained detectable levels of VZV IgG antibodies, reflecting the VZV antibody levels in the population today.’ To check serum quality, VZV IgG antibodies of the serum samples were detected by an in-house ELISA. In this study, the serum samples were detected by Borrelia whole-cell sonicate screening test and further confirmed by C6 Lyme ELISA test and recomBead IgG 2.0 assay [[3]van Beek J. Sajanti E. Helve O. Ollgren J. Virtanen M.J. Rissanen H. et al.Population-based Borrelia burgdorferi sensu lato seroprevalence and associated risk factors in Finland.Ticks Tick Borne Dis. 2018; 9: 275-280Crossref PubMed Scopus (16) Google Scholar]. The VZV IgG antibodies did not fully reflect the stability of the IgG antibodies for B. burgdorferi. Furthermore, there are no reports that IgG antibody titres for VZV and B. burgdorferi remain stable during long-term storage. Although the serum samples were stored at −20°C, the IgG antibody titres may degrade after 50 years. To minimize antibody degradation, the serum samples should be transferred as several separate aliquots in cryotubes and stored in cold-chain or liquid nitrogen from collection to transportation. These processes should be undertaken under sterile conditions. The samples should subsequently be placed at −70°C or −80°C for long-term storage before laboratory analysis. The collection and preparation of the serum samples in each district and transportation to the lab should take an average of 5 to 7 days [[4]Burimuah V. Sylverken A. Owusu M. El-Duah P. Yeboah R. Lamptey J. et al.Sero-prevalence, cross-species infection and serological determinants of prevalence of bovine coronavirus in cattle, sheep and goats in Ghana.Vet Microbiol. 2020; 241: 108544Crossref PubMed Scopus (12) Google Scholar]. Notably, the relationship between IgG antibodies for B. burgdorferi and storage conditions needs further investigation [[5]Zhao J. A comment on ‘Factors influencing the outcome of primary immunization against rabies in young dogs.Vet Microbiol. 2019; 228: 259Crossref PubMed Scopus (7) Google Scholar]. On the one hand, if the seropositive samples for B. burgdorferi from this study are still being stored, we strongly believe that they should be tested by the same methods in the future [[1]Cuellar J. Dub T. Sane J. Hytönen J. Seroprevalence of Lyme borreliosis in Finland 50 years ago.Clin Microbiol Infect. 2019 Oct 14; (S1198-743X(19)30530-0)Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar]. On the other hand, the LB seroprevalence among the general population was investigated in Finland in 2011 [[3]van Beek J. Sajanti E. Helve O. Ollgren J. Virtanen M.J. Rissanen H. et al.Population-based Borrelia burgdorferi sensu lato seroprevalence and associated risk factors in Finland.Ticks Tick Borne Dis. 2018; 9: 275-280Crossref PubMed Scopus (16) Google Scholar]. If the serum samples were stored at −20°C till now, the seropositive samples should be detected now to investigate the stability of IgG antibodies for B. burgdorferi after 9 years' storage. The collection, preparation, transportation and storage conditions of the serum samples should be described in the Materials and Methods sections of future seroprevalence studies of LB. Financial support was received from the Foundation of Liaocheng University (grant 318011907) and the Doctoral Foundation of Liaocheng University (grants 318051738 and 318051827). All authors report no conflicts of interest relevant to this article. Seroprevalence of Lyme borreliosis in Finland 50 years agoClinical Microbiology and InfectionVol. 26Issue 5PreviewLyme borreliosis (LB) is a tick-borne infection common in Europe. In Finland, the LB seroprevalence in the healthy population was 3.9% in 2011. While the present-day seroprevalence of LB is well characterized in several European areas, there are no studies on the seroprevalence of LB before the description of the infection in the late 1970s. Full-Text PDF Open Access'Seroprevalence of Lyme borreliosis in Finland 50 years ago' – Author’s replyClinical Microbiology and InfectionVol. 26Issue 7PreviewWe read with keen interest the comments on ‘Seroprevalence of Lyme borreliosis in Finland 50 years ago.’ Zhang et al. questioned the effect of long-term storage on the stability of Borrelia antibodies in serum samples. Further, they suggested retesting the Borrelia antibodies in the serum samples collected in 2011. Full-Text PDF Open Archive

[1]. College of Animal Veterinary Medicine, Jilin Agricultural Science and Technology University, Jilin 132101, China. [2]. Key Laboratory of Jilin Province for Zoonoses Prevention and Control, Laboratory of Epidemiology, Institute of Military Veterinary Medicine, Academy of Military Medical Sciences, Changchun 130122, China. [3]. Jilin Agricultural University, Changchun 130118, China. [4]. Changchun Sci-Tech University, 1699 Donghua street, Shuangyang District, Changchun 130600, China. [5]. Xuzhou Medical University, Xuzhou 221004, China.

Dengue is an increasing medical problem in subtropical and tropical countries. The search for a safe and effective vaccine is complicated by the fact that there are four types of dengue virus and that, if a vaccine is live attenuated, it should be proven not to cause the life-threatening form of dengue, dengue haemorrhagic fever. So far one vaccine candidate, a four-valent chimeric vaccine constructed from a yellow fever vaccine strain, has reached large clinical trials and has been shown to offer protection against dengue types 1, 3 and 54 but not against dengue type 2. It is highly likely that an effective vaccine will be available in the next decade.

1Jilin Academy of Animal Husbandry and Veterinary Medicine, Changchun, China. 2Scientific Research Center, Guilin Medical University, Guilin, China. 3 Department of Clinical laboratory, China-Japan Union Hospital of Jilin University, Changchun, China. 4 Huanren County Agricultural Development Service Center, Huanren, Liaoning, China. 5 Laboratory of Infectious Diseases, College of Veterinary Medicine, Key Laboratory of Zoonosis Research, Ministry of Education, Jilin University, Changchun, China. 6 Changchun Sci-Tech University, Changchun, China. (Correspondence to: Jinghui Zhao: zhaojinghui8791@hotmail.com).

Pharmacological agents that raise cAMP and activate protein kinase A (PKA) stimulate 26S proteasome activity, phosphorylation of subunit Rpn6, and intracellular degradation of misfolded proteins. We investigated whether a similar proteasome activation occurs in response to hormones and under various physiological conditions that raise cAMP. Treatment of mouse hepatocytes with glucagon, epinephrine, or forskolin stimulated Rpn6 phosphorylation and the 26S proteasomes' capacity to degrade ubiquitinated proteins and peptides. These agents promoted the selective degradation of short-lived proteins, which are misfolded and regulatory proteins, but not the bulk of cell proteins or lysosomal proteolysis. Proteasome activities and Rpn6 phosphorylation increased similarly in working hearts upon epinephrine treatment, in skeletal muscles of exercising humans, and in electrically stimulated rat muscles. In WT mouse kidney cells, but not in cells lacking PKA, treatment with antidiuretic hormone (vasopressin) stimulated within 5-minutes proteasomal activity, Rpn6 phosphorylation, and the selective degradation of short-lived cell proteins. In livers and muscles of mice fasted for 1248 hours cAMP levels, Rpn6 phosphorylation, and proteasomal activities increased without any change in proteasomal content. Thus, in vivo cAMP-PKA-mediated proteasome activation is a common cellular response to diverse endocrine stimuli and rapidly enhances the capacity of target tissues to degrade regulatory and misfolded proteins (e.g., proteins damaged upon exercise). The increased destruction of preexistent regulatory proteins may help cells adapt their protein composition to new physiological conditions.

•More samples from the natural infection cattle of rabies virus were collected, more findings would be revealed.•The molecular characterization and epidemiology analysis of cattle rabies should be constantly investigated in Brazil.•The epidemiological data might be the foundation for the control of rabies in the future.