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Journal ArticleDOI

Modified-Live Feline Calicivirus Vaccination Reduces Viral RNA Loads, Duration of RNAemia, and the Severity of Clinical Signs after Heterologous Feline Calicivirus Challenge

30 Jul 2021-Viruses (Multidisciplinary Digital Publishing Institute)-Vol. 13, Iss: 8, pp 1505
TL;DR: In this article, the authors investigated the clinical signs, duration, and amount of FCV shedding, RNAemia, haematological changes and acute phase protein reaction in SPF cats after subcutaneous modified-live single strain FCV vaccination or placebo injection and two subsequent oronasal heterologous FCV challenge infections with two different field strains.
Abstract: Feline calicivirus (FCV) is a common cat virus causing clinical signs such as oral ulcerations, fever, reduced general condition, pneumonia, limping and occasionally virulent-systemic disease. Efficacious FCV vaccines protect against severe disease but not against infection. FCV is a highly mutagenic RNA virus whose high genetic diversity poses a challenge in vaccine design. The use of only one modified-live FCV strain over several decades might have driven the viral evolution towards more vaccine-resistant variants. The present study investigated the clinical signs, duration, and amount of FCV shedding, RNAemia, haematological changes and acute phase protein reaction in SPF cats after subcutaneous modified-live single strain FCV vaccination or placebo injection and two subsequent oronasal heterologous FCV challenge infections with two different field strains. Neither clinical signs nor FCV shedding from the oropharynx and FCV RNAemia were detected after vaccination. After the first experimental infection, vaccinated cats had significantly lower clinical scores, less increased body temperature and lower acute phase protein levels than control cats. The viral RNA loads from the oropharynx and duration and amount of RNAemia were significantly lower in the vaccinated animals. No clinical signs were observed in any of the cats after the second experimental infection. In conclusion, FCV vaccination was beneficial for protecting cats from severe clinical signs, reducing viral loads and inflammation after FCV challenge.
Citations
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Journal ArticleDOI
29 Apr 2022-Viruses
TL;DR: The European Advisory Board on Cat Diseases (ABCD), a scientifically independent board of experts in feline medicine from 11 European countries, presents the current knowledge of FCV infection and fills gaps with expert opinions.
Abstract: Feline calicivirus (FCV) is a common pathogen in domestic cats that is highly contagious, resistant to many disinfectants and demonstrates a high genetic variability. FCV infection can lead to serious or even fatal diseases. In this review, the European Advisory Board on Cat Diseases (ABCD), a scientifically independent board of experts in feline medicine from 11 European countries, presents the current knowledge of FCV infection and fills gaps with expert opinions. FCV infections are particularly problematic in multicat environments. FCV-infected cats often show painful erosions in the mouth and mild upper respiratory disease and, particularly in kittens, even fatal pneumonia. However, infection can be associated with chronic gingivostomatitis. Rarely, highly virulent FCV variants can induce severe systemic disease with epizootic spread and high mortality. FCV can best be detected by reverse-transcriptase PCR. However, a negative result does not rule out FCV infection and healthy cats can test positive. All cats should be vaccinated against FCV (core vaccine); however, vaccination protects cats from disease but not from infection. Considering the high variability of FCV, changing to different vaccine strain(s) may be of benefit if disease occurs in fully vaccinated cats. Infection-induced immunity is not life-long and does not protect against all strains; therefore, vaccination of cats that have recovered from caliciviral disease is recommended.

12 citations

Journal ArticleDOI
31 Aug 2021-Viruses
TL;DR: In this paper, the authors investigated the cellular and humoral immune response of specified pathogen-free (SPF) cats after modified-live FCV F9 vaccinations and two heterologous FCV challenges by the analysis of lymphocyte subsets, cytokine mRNA transcription levels, interferon (IFN)-γ release assays in peripheral blood mononuclear cells (PBMCs), anti-FCV antibodies, and neutralisation activity.
Abstract: Feline calicivirus (FCV) is a common cat virus associated with oral ulcerations and virulent-systemic disease. Efficacious FCV vaccines protect against severe disease but not against infection. The high genetic diversity of FCV poses a challenge in vaccine design. Protection against FCV has been related to humoral and cellular immunity; the latter has not been studied in detail. This study investigates the cellular and humoral immune response of specified pathogen-free (SPF) cats after modified-live FCV F9 vaccinations and two heterologous FCV challenges by the analysis of lymphocyte subsets, cytokine mRNA transcription levels, interferon (IFN)-γ release assays in peripheral blood mononuclear cells (PBMCs), anti-FCV antibodies, and neutralisation activity. Vaccinated cats developed a Th1 cytokine response after vaccination. Vaccination resulted in antibodies with neutralising activity against the vaccine but not the challenge viruses. Remarkably, IFN-γ-releasing PBMCs were detected in vaccinated cats upon stimulation with the vaccine strain and the first heterologous FCV challenge strain. After the first experimental infection, the mRNA transcription levels of perforin, granzyme B, INF-γ, and antiviral factor MX1 and the number of IFN-γ-releasing PBMCs when stimulated with the first challenge virus were higher in vaccinated cats compared to control cats. The first FCV challenge induced crossneutralising antibodies in all cats against the second challenge virus. Before the second challenge, vaccinated cats had a higher number of IFN-γ-releasing PBMCs when stimulated with the second challenge virus than control cats. After the second FCV challenge, there were less significant differences detected between the groups regarding lymphocyte subsets and cytokine mRNA transcription levels. In conclusion, modified-live FCV vaccination induced cellular but not humoral crossimmunity in SPF cats; innate immune mechanisms, secretory and membranolytic pathways, and IFN-γ-releasing PBMCs seem to be important in the host immune defence against FCV.

3 citations

Journal ArticleDOI
TL;DR: Two sensitive and visual assays for FCV nucleic acid detection based on RPA reaction and CRISPR-Cas13a trans-cleavage activity are developed and provided reliable and visual diagnostic alternatives forFCV field detection.
Abstract: Feline calicivirus (FCV) is a well-known causative pathogen for upper respiratory infection in cats. Its high genetic variability challenges existing molecular diagnostic methods in clinical settings. Thus, we developed two sensitive and visual assays for FCV nucleic acid detection based on RPA reaction and CRISPR-Cas13a trans-cleavage activity. Recombinant plasmid DNA, crRNAs, and RPA primers were designed and prepared, respectively, targeting to FCV ORF1 gene. Besides, purified LwCas13a protein was produced by E.coli prokaryotic expression system. To confirm the validity of FCV-Cas13a assays, seven reaction systems (RSs) with different components were tested, and visual readouts were displayed by lateral flow dipstick (FCV-Cas13a-LFD) and fluorescence detector (FCV-Cas13a-FLUOR), respectively. The established FCV-Cas13a assays were capable of detecting FCV nucleic acid in presetting RSs without cross-reaction with other feline-associated pathogens, and the detection limit was as low as 5.5 copies/μl for both visual methods. Moreover, the positive rate of 56 clinical specimens detected by FCV-Cas13a assays (67.9%, 38/56) was notably higher than that of RT-qPCR (44.6%, 25/56) (p < 0.001), including 13 presumptive positive specimens. Taken together, FCV-Cas13a assays provided reliable and visual diagnostic alternatives for FCV field detection.

3 citations

Journal ArticleDOI
TL;DR: Wang et al. as mentioned in this paper provided the first research to the authors' knowledge that provides epidemiological results of FURI in cats in Wuhan region of China, which revealed that the strains connected with the F9 and 255 vaccines were distant, which may lead to vaccination failure.
Abstract: Simple Summary Feline upper respiratory infection (FURI) is a frequent ailment in felines. It feels like a cold, but it has the potential to be far worse. Such infections in cats are most often caused by viruses, perhaps between 80% and 90%, while bacteria are responsible for the remaining 10% or so. Clinical sign analysis revealed that feline calicivirus (FCV) infections were most often linked with oral symptoms, whereas feline herpesvirus (FHV) infections were most often consorted with sneezing. It is the first research to the authors’ knowledge that provides epidemiological results of FURI in cats in Wuhan region of China. Every veterinarian may benefit from the outcomes described, since doing so will refresh their understanding of FURI. Anticipating the development of a more phylogenetically similar FCV vaccine, we discovered that the strains connected with the F9 and 255 vaccines were distant, which may lead to vaccination failure. Hence, it is necessary to encourages geographically specific FCV vaccine. Abstract A total of 1158 cats with feline upper respiratory tract infection were incorporated from twenty animal hospitals in Wuhan, China, from April 2019 to April 2022 to investigate the epidemiology of feline calicivirus (FCV), herpesvirus-1 (FHV-1), Mycoplasma felis (M. felis) and Chlamydia felis (C. felis) for the development of a geographically-specific FCV vaccine with reference to prevalence and risk factors for infection. The 871 samples (75.2%) of kittens were younger than 12 months, of which 693 were males, and 456 were females. Among the samples, 443 were British shorthair cats, accounting for 38.3%, and 252 were Chinese rural cats, accounting for 21.8%. PCR/RT-PCR detection of the above four viruses (FCV, FHV-1, M. felis, and C. felis) in the upper respiratory tract of cats showed that the total positive samples were 744 (64.3%), including 465 positive samples of feline calicivirus, accounting for 40.2% of the total 1158 samples. There were 311 positive samples of M. felis, accounting for 26.9% of the total samples, ranked second in clinical practice. The 180 positive samples of feline herpesvirus accounted for 15.5%, and 85 positive samples of Chlamydia felis accounted for 7.3%. Among them, the number of positive samples of single pathogenic infections was 493, accounting for 66.3% of the total 744 positive samples. Double, triple, and quadruple infections accounted for 28.2%, 5.0%, and 0.5%, respectively, with the highest proportion of single infections. The molecular biological characteristics of the 17 isolated FCVd strains in Wuhan were further analyzed. It was found that the F9 vaccine strain and the antigenic epitopes in the 5’HVR of the E region were collated with the F9 vaccine strain. Moreover, phylogenetic tree analysis showed that the strains related to the F9 and 255 vaccines were distantly related, leading to the failure of the vaccine. In addition, the strains associated with the F9 and 255 vaccines were distant, which might lead to vaccine failure in anticipation of the development of a more phylogenetically close FCV vaccine in China and may require the development of a vaccine for a locally related FCV strain.
Journal ArticleDOI
TL;DR: In this paper , a dual ERA method was developed using the Exo probe for a differential detection of cat calicivirus (FCV) and feline herpesvirus type I (FHV-1).
Abstract: Feline calicivirus (FCV) and feline herpesvirus type I (FHV-1) are the most common viral pathogens responsible for cat respiratory diseases, and coinfection with these two pathogens is often found. In veterinary clinics, the main diagnostic methods for FCV and FHV-1 are test strips and polymerase chain reaction (PCR). However, the sensitivity of test strips are not sufficient, and PCR is time-consuming. Therefore, developing a rapid and high-performance clinical diagnostic test is imperative for the prevention and treatment of these diseases. Enzymatic recombinase amplification (ERA) is an automated isothermal nucleic acid amplification technique that maintains a constant temperature, and is both rapid and highly accurate. In this study, a dual ERA method was developed using the Exo probe for a differential detection of FCV and FHV-1. This dual ERA method demonstrated high performance with the detection limit of 101 copies for both viruses, and no cross-reactions with feline parvovirus virus and F81 cells. To test the utility of the method for clinical applications, 50 nasopharyngeal swabs from cats with respiratory symptoms were collected and tested. The positive rates of FCV and FHV-1 were 40% (20/50, 95% confidence interval [CI], 26.4 to 54.8%) and 14% (7/50, 95% CI, 5.8 to 26.7%), respectively. The rate of coinfection with FCV and FHV-1 was 10% (5/50, 95% CI, 3.3 to 21.8%). These results were in agreement with those found using quantitative real-time PCR. Therefore, this dual ERA method is a novel and efficient clinical diagnostic tool for FCV and FHV-1 detection.
References
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Book
12 Aug 2005
TL;DR: Part I: Viral, Rickettsial, And Mycoplasmal Diseases, and Part II: Clinical Problems.
Abstract: Section I: Viral, Rickettsial, And Mycoplasmal Diseases. Laboratory Diagnosis of Viral and Rickettsial Infections. Antiviral Drugs. Canine Distemper. Infectious Canine Hepatitis and Canine Acidophil Cell Hepatitis. Canine Herpesvirus Infection. Canine Infectious Tracheobronchitis. Nonrespiratory Parainfluenza Virus Infection of Dogs. Canine Viral Enteritis. Canine Viral Papillomatosis. Feline Panleukopenia. Feline Coronavirus Infection. Feline Enteric Viral Infections. Feline Viral Neoplasia. Feline Immunodeficiency Virus Infection. Feline Adenovirus Infection. Feline Respiratory Disease. Feline Syncytium-Forming Virus Infection. Feline Paramyxovirus Infections. Feline Poxvirus Infection. Hantavirus Infection. Feline Viral Papillomatosis. Rabies. Pseudorabies. Enterovirus Infections. Mumps and Influenza Virus Infections. Arboviral Infections. Salmon Poisoning Disease. Ehrlichiosis. Rocky Mountain Spotted Fever, Q Fever, And Typhus. Haemobartonellosis. Chlamydial Infections. Mycoplasmal, Ureaplasmal, And L-Form Infections. Section Ii: Bacterial Diseases. Laboratory Diagnosis of Bacterial Infections. Antibacterial Chemotherapy. Streptococal and Other Gram-Positive Bacterial Infections. Staphylococcal Infections. Gram-Negative Bacterial Infections. Endotoxemia. Enteric Bacterial Infections. Canine Brucellosis. Anaerobic Infections. Botulism. Tetanus. Leptospirosis. Lyme Borreliosis. Miscellaneous Bacterial Infections. Plague. Tularemia. Actinomycosis and Nocardiosis. Mycobacterial Infections. Dermatophilosis. Feline Abscesses. Bite Wound Infections. Bartonellosis. Surgical and Traumatic Infections. Section Iii: Fungal Diseases. Laboratory Diagnosis of Fungal and Algal Infections. Antifungal Chemotherapy. Dermatophytosis. Blastomycosis. Histoplasmosis. Cryptococcosis. Coccidioidomycosis. Sporotrichosis. Rhinosporidiosis. Aspergillosis and Penicilliosis. Candidiasis, Torulopsosis, And Rhodotorulosis. Trichospornosis. Miscellaneous Fungal Infections. Prothotecosis. Section Iv: Protozoal Diseases. Laboratory Diagnosis of Protozoal Infections. Antiprotozoal Chemotherapy. Trypanosomiasis. Leishmaniasis. Hepatozoonosis. Encephalitozoonosis. Cytauxzoonosis. Babesiosis. Enteric Protozoal Infections. Acanthamebiasis. Toxoplasmosis and Neosporosis. Enteric Coccidiosis. Cryptosporidiosis and Cyclosporiasis. Pneumocystosis. Neurologic Diseases of Suspected Infectious Origin. Section V: Clinical Problems. Integumentary Infections. Musculoskeletal Infections. Cardiovascular Infections. Respiratory Infections. Gastrointestinal and Intra-Abdominal Infections. Hepatobiliary Infections. Genitourinary Infections. Central Nervous System Infections. Ocular Infections. Environmental Factors in Infectious Diseases. Immunodeficiencies and Infectious Diseases. Fever. Prevention and Management of Infection in Catteries. Prevention and Management of Infections in Kennels. Immunocompromised People and Pets. Immunoprophylaxis and Immunotherapy. Appendices: Canine Immunization Recommendations. Feline Immunization Recommendations. Canineand Feline Biologics Manufacturers and Products Available Worldwide. Compendium of Animal Rabies Control, 1998 National Association of State Public Health Veterinarians, Inc. Laboratory Testing for Infectious Diseases of Dogs and Cats. Manufacturers of Diagnostic Test Kits and Their Products. Infectious Disease Rule-Outs for Medical Problems. Antimicrobial Drug Formulary.

1,367 citations

Journal Article
TL;DR: The passive transfer of local immunity by the i.v. administration of pIgA antibody is demonstrated and it is shown that the IgA in secretions can protect against influenza virus infection.
Abstract: Secretory IgA is presumed to be the mediator of mucosal immunity based on many studies that show a correlation between protection and secretory IgA titers; however, a causal relationship has not yet been established. Classically, passive transfer of antibody has been used to demonstrate causality, but the passive transfer of local immunity with physiologically transported IgA has not been previously reported. In this study mice were injected intravenously with polymeric IgA (pIgA), monomeric IgA (mIgA), or IgG1 mAb specific for the H1 hemaglutinin of PR8 influenza virus. pIgA was shown to be specifically transported into nasal secretions relative to the mIg. The transported pIgA was functional, as evidenced by its ability to bind to virus in an ELISA assay and to protect nonimmune mice against intranasal infection with H1N1 but not H3N2 influenza virus. Intravenous injection of similar virus-neutralizing doses of anti-influenza IgG1 mAb did not protect against nasal viral challenge. IgA-mediated protection could be abrogated by the intranasal administration of antiserum against the alpha chain of IgA. These data demonstrate the passive transfer of local immunity by the i.v. administration of pIgA antibody and show that the IgA in secretions can protect against influenza virus infection. This general approach could provide a model for the evaluation of the role of local IgA in host defense against other pathogens.

338 citations

Journal ArticleDOI
TL;DR: It appears that local secretory IgA plays a causal role in the prevention of cross‐infection by influenza A virus and serum antibody and Tc cells, on the other hand, may be crucial for recovery from such infection.
Abstract: Mice previously infected with an aerosol of A/Rec 31 influenza virus were strongly protected against an aerosol challenge with A/Vic influenza as judged by lung virus titers recovered 2 days after the challenge infection. Such complete homotypic immunity was not achieved by priming with live Rec 31 virus injected i.v. or UV-inactivated Rec 31 virus administered s.c. together with Al(OH)3 and saponin. The reason for the superior protective effect of the natural infection was investigated. The protection induced by respiratory infection with Rec 31 virus was specific for influenza A viruses. It was not correlated with specific serum hemagglutination inhibition antibody titer or cross-reactive cytotoxic T (Tc) cell reactivity. Moreover, the transfer of splenic and lymphoid T cell populations with strong secondary Tc activity did not significantly reduce lung virus titers in recipient mice 3 days after infection. The protection however occurred in parallel with the presence of cross-reactive IgA antibody in the lung washings. It thus appears that local secretory IgA plays a causal role in the prevention of cross-infection by influenza A virus. Serum antibody and Tc cells, on the other hand, may be crucial for recovery from such infection. All mice primed with live Rec 31 virus, administered i.v. or by aerosol and expressing equally high levels of Tc reactivity, survived a lethal challenge with A/PR8 virus. The same challenge, however, killed half of the mice immunized s.c. with inactivated Rec 31 virus which induced only a low level of Tc reactivity.

322 citations

Journal ArticleDOI
TL;DR: The WSAVA Vaccination Guidelines Group (VGG) was formed in 2006 with the responsibility of producing global vaccination guidelines for dogs and cats that would consider international differences in economic and societal factors that impact on the keeping of these small companion animals.
Abstract: The WSAVA Vaccination Guidelines Group (VGG) was convened in 2006 with the responsibility of producing global vaccination guidelines for dogs and cats that would consider international differences in economic and societal factors that impact on the keeping of these small companion animals. They were launched at the 2007 WSAVA Congress and contemporaneously published in the Journal of Small Animal Practice (Day et al., 2007). English and Spanish versions were made publicly available on the WSAVA website. With recognition that this is a rapidly developing field of companion animal medicine, the VGG was reconvened in 2009 with the targets of (1) updating the 2007 guidelines for veterinarians and (2) preparing a new set of guidelines directed at the owners and breeders of dogs and cats. The VGG has met on three occasions during 2009–2010 and has had active electronic communication between these meetings. The present document represents the conclusion of the first target, and the VGG is well progressed towards the launch of owner‐breeder guidelines in 2010. The first activity of this second phase of the VGG was to assess the impact of the 2007 guidelines on the international veterinary community. To achieve this goal, it developed a simple questionnaire that was circulated to all 70 WSAVA member countries through their WSAVA Assembly representatives. The following questions were asked: 1 Were the 2007 guidelines widely available to veterinarians in your country? 2 Were the 2007 guidelines discussed by your national small animal veterinary association? 3 Does your national small animal veterinary association have its own guidelines for the vaccination of dogs and cats? 4 If not, has your national small animal veterinary association adopted the WSAVA guidelines? 5 Is there any significant conflict between the WSAVA guidelines and national practices in companion animal medical care? Each country that had its own vaccination guidelines was also asked to send a copy of these to the VGG. Responses were received from 27 countries, both from developed and developing nations. The 2007 guidelines were generally accessible by the veterinary community (for 18 of 27 respondents); where this was not the case, the reason was most often the unavailability of a translated version. Notably, the lack of computers and internet access in general practice was also flagged by some developing nations. The 2007 guidelines had been discussed by the small animal veterinary associations of 12 of 27 respondent countries. Thirteen of 27 respondent countries already had national guidelines in place or in the case of some smaller European countries had adopted those used by a larger neighbour. The VGG was privileged to be able to assess six of these national guidelines documents, which ranged from excellent succinct summaries to very detailed and substantial papers that provided solid background discussion of immunology and vaccination. The VGG was pleased to note that in 12 of 14 countries without vaccination guidelines, the national organizations had either fully adopted or recommended the WSAVA guidelines or were currently using them to develop their own national recommendations. It is also clear that in some countries, publication of the guidelines had precipitated discussion by national organizations that had sometimes been driven by pressure from the general public. Most respondents indicated a range of minor conflicts between the WSAVA guidelines and national practice, but these were not as great as anticipated. For example, many countries maintain legal annual revaccination for rabies, some countries do not have access to the full range of products listed in the guidelines (e.g. individual component products or extended DOI products), and others have specific national products from local manufacturers that are not globally available. The responses to this questionnaire underline the importance of global vaccination guidelines and of their current revision. The aim of this document is to update and extend the information given in the 2007 version; while much of the text and recommendations will remain the same, specific changes are: 1 A clear indication of the purpose of a guidelines document. 2 A discussion of passive immunization, in particular for canine distemper virus (CDV) infection. 3 Preliminary assessment of vaccines for canine influenza virus (CIV), leishmaniosis and malignant melanoma. 4 Discussion of differences in approach to feline upper respiratory virus (FHV‐1 and FCV) and feline leukaemia virus (FeLV) vaccination. 5 Recommendations for sites of vaccination for cats. 6 An update on cross‐protection for canine parvovirus (CPV) 2c. 7 A new fact sheet on rabies vaccines. 8 An expanded list of 60 frequently asked questions (FAQs). Feedback suggested that this aspect of the 2007 guidelines document was particularly useful to practitioners. 9 An image bank of major canine and feline vaccine‐preventable diseases. The VGG believes that these images will be of great value to the practicing veterinarian during the ‘vaccination interview’ with clients. The images are freely available via the WSAVA website and provide visual evidence of the significance and severity of infectious diseases that may be prevented by vaccination. The images may be used in the consultation room whilst addressing the ‘risk‐benefit’ of vaccination with pet owners. The VGG again acknowledges the important work undertaken by the American Animal Hospital Association (AAHA) Canine Vaccine Task Force (Paul et al., 2006) and the American Association of Feline Practitioners (AAFP) Feline Vaccine Advisory Panel (Richards et al., 2006) in addressing companion animal vaccination issues. Since publication of the 2007 WSAVA guidelines, the European Advisory Board on Cat Diseases (ABCD) has also formulated recommendations for feline vaccination from the European perspective, and the work of this group has recently cumulated in publication of a special issue of the Journal of Feline Medicine and Surgery (Horzinek and Thiry, 2009).

230 citations

Journal ArticleDOI
TL;DR: Feline herpesvirus infections cause acute rhinitis and conjunctivitis, usually accompanied by fever, depression and anorexia, and in most cats, FHV remains latent after recovery, and they become lifelong virus carriers.
Abstract: Overview Feline viral rhinotracheitis, caused by feline herpesvirus (FHV), is an upper respiratory tract disease that is often associated with feline calicivirus and bacteria. In most cats, FHV remains latent after recovery, and they become lifelong virus carriers. Stress or corticosteroid treatment may lead to virus reactivation and shedding in oronasal and conjunctival secretions.

202 citations