Immune response induced by a Streptococcus suis multi-serotype autogenous vaccine used in sows to protect post-weaned piglets.

Streptococcus suis is a bacterial pathogen that causes important economic losses to the swine industry worldwide. Since there are no current commercial vaccines, the use of autogenous vaccines applied to gilts/sows to enhance transfer of passive immunity is an attractive alternative to protect weaned piglets. However, there is no universal standardization in the production of autogenous vaccines and the vaccine formulation may be highly different among licenced manufacturing laboratories. In the present study, an autogenous vaccine that included S. suis serotypes 2, 1/2, 5, 7 and 14 was prepared by a licensed laboratory and administrated to gilts using a three-dose program prior to farrowing. The antibody response in gilts as well as the passive transfer of antibodies to piglets was then evaluated. In divergence with previously published data with an autogenous vaccine produced by a different company, the increased response seen in gilts was sufficient to improve maternal antibody transfer to piglets up to 5 weeks of age. However, piglets would still remain susceptible to S. suis disease which often appears during the second part of the nursery period. Vaccination did not affect the shedding of S. suis (as well as that of the specific S. suis serotypes included in the vaccine) by either gilts or piglets. Although all antibiotic treatments were absent during the trial, the clinical protective effect of the vaccination program with the autogenous vaccine could not be evaluated, since limited S. suis cases were present during the trial, confirming the need for a complete evaluation of the clinical protection that must include laboratory confirmation of the aetiological agent involved in the presence of S. suis-associated clinical signs. Further studies to evaluate the usefulness of gilt/sow vaccination with autogenous vaccines to protect nursery piglets should be done.

Advancement of Autogenous Vaccines in the Poultry Industry.

Autogenous vaccines, also known as "custom" vaccines, have become an essential instrument in the production veterinarian's toolbox for the control of emerging and evolving diseases. Autogenous vaccines require a reduced burden of U.S. Department of Agriculture licensing, making them rapidly accessible. Autogenous vaccines have made significant advancements in the ability to reduce disease within the poultry industry from a combination of several different advancements in regulation requirements, rapid and accurate diagnostic assessments, and improvements in manufacturing. The use of autogenous vaccines by poultry health professionals has also increased, and these custom-made products have been instrumental in combating diseases resulting from antigenic variants such as salmonellosis, colibacillosis, infectious coryza, infectious bursal disease, inclusion body hepatitis, viral enteritis, and viral arthritis and tenosynovitis.

Estudio recapitulativo- Avance de las vacunas autógenas en la industria avícola Las vacunas autógenas, también conocidas como vacunas "personalizadas, elaboradas de acuerdo con las necesidades del cliente" ("custom"), se han convertido en un instrumento esencial en el inventario de herramientas del veterinario de producción para el control de enfermedades emergentes y en evolución. Las vacunas autógenas requieren un procedimiento reducido para obtener la licencia por parte del Departamento de Agricultura de los Estados Unidos, lo que las hace rápidamente accesibles. Las vacunas autógenas han logrado avances significativos en la capacidad de reducir enfermedades dentro de la industria avícola gracias a una combinación de varios avances diferentes en los requisitos regulatorios, evaluaciones de diagnóstico rápidas y precisas y mejoras en la fabricación. También ha aumentado el uso de vacunas autógenas por parte de los profesionales de la salud avícola, y estos productos hechos a medida han sido fundamentales para combatir enfermedades resultantes de variantes antigénicas como la salmonelosis, la colibacilosis, la coriza infecciosa, la enfermedad infecciosa de la bolsa, hepatitis con cuerpos de inclusión, la enteritis viral y la artritis y tenosinovitis virales.

Veterinary Autogenous Vaccines for Poultry in Europe-Many Ways to Crack an Egg.

In the past decade, European animal farming has increasingly used autogenous vaccines for the prevention of nonnotifiable diseases. In Europe, these vaccines are exclusively inactivated bacterial and viral vaccines, with a set of specific regulations that differentiate them from conventional vaccines. The highest number of applications most likely occurs in poultry, as these animal species are farmed in the highest numbers compared with other types of food-producing animals. In 2019, autogenous vaccines came within the scope of harmonized European regulation for the first time, although many important aspects are still missing and need to be further developed. Consequently, several important legal provisions remain in national legislations and can vary tremendously between different member states of the European Union. The inclusion of autogenous vaccines in the management of certain diseases of poultry is justified by the nonavailability of licensed vaccines and the evolution and diversity of antigens in the field that are not covered by licensed vaccines. In addition, these vaccines aid in reducing the use of antibiotics. The methods for isolating and typing pathogenic isolates to obtain relevant antigens are pathogen specific and require a careful approach based on clinical evidence. Manufacturing processes are optimized according to regulatory standards, and they represent the most critical factor influencing the quality of autogenous vaccines and their placement on the market. This review presents the important requirements for manufacturing autogenous vaccines for poultry in addition to the relevant regulatory considerations. The results from a survey of several European Union member states regarding specific provisions within their national legislations are also presented.

Vacunas veterinarias autógenas para la avicultura en Europa: "Varias formas de romper un huevo". En la última década, la ganadería europea ha utilizado cada vez más vacunas autógenas para la prevención de enfermedades no declarables. En Europa, estas vacunas son exclusivamente vacunas inactivadas bacterianas y virales, con un conjunto de regulaciones específicas que las diferencian de las vacunas convencionales. El mayor número de aplicaciones probablemente se produce en la avicultura, ya que estas especies animales se crían en mayor número en comparación con otros tipos de animales productores de alimentos. En el año 2019, las vacunas autógenas entraron por primera vez en el ámbito de aplicación de una regulación europea armonizada, aunque todavía faltan muchos aspectos importantes y es necesario desarrollarlos más. En consecuencia, varias disposiciones legales importantes permanecen en las legislaciones nacionales y pueden variar enormemente entre los diferentes estados miembros de la Unión Europea. La inclusión de vacunas autógenas en el manejo de determinadas enfermedades avícolas se justifica por la falta de disponibilidad de vacunas autorizadas y la evolución y diversidad de antígenos en el campo que no están cubiertos por vacunas con licencia. Además, estas vacunas ayudan a reducir el uso de antibióticos. Los métodos para aislar y tipificar aislados patógenos para obtener antígenos relevantes son específicos de cada patógeno y requieren un enfoque cuidadoso basado en evidencia clínica. Los procesos de fabricación se optimizan de acuerdo con las normas reglamentarias y representan el factor más crítico que influye en la calidad de las vacunas autógenas y su comercialización. Esta revisión presenta los requisitos importantes para la fabricación de vacunas autógenas en la avicultura, además de las consideraciones regulatorias relevantes. También se presentan los resultados de una encuesta realizada en varios estados miembros de la Unión Europea sobre disposiciones específicas dentro de sus legislaciones nacionales.

Protection of laying chickens against the Canadian DMV/1639 infectious bronchitis virus infection through priming with heterologous live vaccine and boosting with heterologous or homologous inactivated vaccine.

The emergence of the Canadian Delmarva (DMV)/1639 infectious bronchitis virus (IBV) type strains was associated with egg production disorders in Eastern Canadian layer operations. While developing vaccines for novel IBV variants is not typically a reasonable approach, the consideration of an autogenous vaccine becomes more appealing, particularly when the new variant presents significant economic challenges. The current study aimed to compare the efficacies of two vaccination programs that included heterologous live priming by Massachusetts (Mass) and Connecticut (Conn) type vaccines followed by either a commercial inactivated Mass type vaccine or a locally prepared autogenous inactivated DMV/1639 type vaccine against DMV/1639 IBV challenge. The protection parameters evaluated were egg production, viral shedding, dissemination of the virus in tissues, gross and microscopic lesions, and immunological responses. The challenge with the DMV/1639 caused severe consequences in the non-vaccinated laying hens including significant drop in egg production, production of low-quality eggs, serious damage to the reproductive organs, and yolk peritonitis. The two vaccination programs protected the layers from the poor egg-laying performance and the pathology. The vaccination program incorporating the autogenous inactivated DMV/1639 type vaccine was more effective in reducing vial loads in renal and reproductive tissues. This was associated with a higher virus neutralization titer compared to the group that received the commercial inactivated Mass type vaccine. Additionally, the autogenous vaccine boost led to a significant reduction in the viral shedding compared to the non-vaccinated laying hens. However, both vaccination programs induced significant level of protection considering all parameters examined. Overall, the findings from this study underscore the significance of IBV vaccination for protecting laying hens.

Autovaccines - potent tool against chronic vulvovaginal candidiasis.

OBJECTIVE: Our aim was to determine the effect of immunomodulatory therapy in women with chronic and recurrent vulvovaginal candidiasis (RVVC). BACKGROUND: We present recent highlights in the research into vaginal microbiome and consequences of chronic inflammation such as vulvovaginal candidiasis (VVC). VVC is a widespread vaginal infection primarily caused by Candida albicans. Experience of more than three episodes per year is defined as RVVC. METHODS: The strains were isolated from women suffering from the above infections as for the period of 2017 to 2021 and subsequently used in immunomodulatory treatment. The preparation and administration of autovaccination therapy was performed using standard methodology and procedures cited in the manuscript. RESULTS: In total, autovaccines were produced for 73 patients of whom 30 (41 %) were successfully cured by this treatment, 29 (40 %) experienced a partially successful treatment, and in the remaining 14 (19 %), the autovaccination therapy was ineffective. CONCLUSION: We provide current knowledge about alternative (autovaccine) treatment options for female patients with VVC and RVVC diseases and our experience with the outcomes after autovaccine administration that currently has a promising therapeutic potential (Tab. 2, Ref. 18). Text in PDF www.elis.sk Keywords: autovaccines, chronic infections, vulvovaginal candidiasis, recurrent, Candida albicans.

Umbilical Outpouchings in two Danish herds raising pigs with minimal use of antibiotics - Results from a field trial evaluating the efficacy of autogenous vaccines and iodine application.

In Denmark, a Pure Pork concept for raising pigs without antibiotics was initiated in 2015 by the Danish Crown slaughterhouse cooperative. Pure Pork herds are characterised by minimal use of antibiotics and pigs are mainly treated individually. An increased prevalence of pigs suffering from umbilical outpouchings (UO) is a considerable challenge for Pure Pork producers. Umbilical outpouchings in pigs are challenging due to reduced welfare and increased workload and cost for the farmer. Therefore, Pure Pork producers require means other than antibiotic treatment to prevent UO. The primary objective of this study was therefore to evaluate the effect of autogenous sow vaccines based on bacteria isolated from the inflamed umbilici of piglets and a 7% iodine treatment at birth on the risk of pigs developing UO during the first 12 weeks of life. In addition, umbilical clinical and necropsy findings were presented, including variation over time and an identification of risk factors. A total of 5852 live-born piglets were included at birth from two Pure Pork herds. In this study, UO was defined as the presence of a rounded outpouching and/or a small firm protrusion at the umbilical area. Among 5614 pigs examined at weeks 5 and 12 and/or at death a total of 534 (9.5%) pigs were recorded with UO. The incidence of outpouchings was 10.2% for Herd A and 8.8% for Herd B. In the present field trial, neither autogenous vaccination of sows nor a 7% iodine spray on the umbilical area of new-born piglets had a statistically significant effect on the incidence of UO, but there was a tendency for a lower risk of UO in pigs treated with iodine spray at birth in one herd (OR = 0.7, p = 0.07), which might be worth investigating further. The risk factors for UO identified in this study included sow parity in one herd with more UO pigs from second parity sows and older compared to gilts (OR = 2.0, p = 0.02), batch in the second herd, and sex in both herds with male pigs at lower risk of UO development compared to female pigs (OR = 0.8, p = 0.006). Furthermore, antibiotic treatment as an indicator of the presence of other diseases resulted in a higher risk of UO compared to untreated pigs (OR = 1.9, p<0.0001). The presence of UO in one pig varied over time; For UO pigs examined alive at both week 5 and 12, 136 pigs (2.4%) had an UO record at week 5 but not at week 12 and 179 pigs (3.2%) did not have an UO at week 5 but a UO record at week 12. For 115 pigs (2.0%) an UO was recorded both at week 5 and week 12.

TbpBY167A-based vaccine is safe in pregnant sows and induces high titers of maternal derived antibodies that reduce Glaesserella parasuis colonization in piglets.

Glässer's disease is one of the main diseases affecting young piglets, particularly during the nursery phase, that can significantly impact pork production. Vaccination of sows has the potential to prevent Glaesserella parasuis infection during the first weeks of life that is to a substantial degree due to the transfer of maternal derived antibodies (MDA) in colostrum. In this study we compare the antibody response to two vaccines administered to pregnant sows. A subunit vaccine containing the mutant transferrin-binding protein, TbpBY167A, and an autogenous vaccine formulated with the LM96/20 strain of G. parasuis (SV4) administered on days 65 and 86 of the gestational period were safe and induced high titers of antibodies in sows. The IgG peak was reached on day 100 of gestation, and the translocation of IgG to the mammary gland was confirmed in colostrum at the time of delivery. Piglets born from vaccinated sows maintained positive IgG titers against TbpBY167A or G. parasuis SV4 for the duration of the experiment (35 days of life). Piglets born from sows vaccinated with the TbpBY167A-based vaccine had a significantly (p = 0.001) lower load of G. parasuis in the respiratory tract compared to those born from sows vaccinated with the autogenous vaccine. Finally, we demonstrate that the LM96/20 (SV4) strain is highly virulent and a primary agent of Glässer's disease.

Effectiveness and health cost analysis between immunoprophylaxis with MV140 autovaccine, MV140 vaccine and continuous treatment with antibiotics to prevent recurrent urinary tract infections.

INTRODUCTION: The objective of this study was to compare the results on prevention of uncomplicated recurrent UTI between continuous use of antibiotics, MV140 autovaccine and MV140 polybacterial vaccine from collection strain. METHODS: 377 patients were prospectively analyzed from January 2017 to August 2019 and divided into 3 groups according to the prophylaxis. Group A (126): antibiotics, Group B (126): MV140 autovaccine, Group C (125): MV140 polybacterial vaccine from the collection strain. Variables analyzed were: gender, age, menopause, number of UTI at baseline and 3 and 6 months after the end of prophylaxis, health cost along follow-up at 3 and 6 months. RESULTS: At 3 months, group A had 0-1 UTI in 65%, group B had 0-1 UTI in 80.8% and group C in 81.7%. At 6 months, group A had 0-1 UTI in 44.4%, group B had 0-1 UTI in 61.6% and group C in 74.6%. Regarding health cost along follow-up, at 3 months group A had euro21,171.87, group B had euro20,763.73 and group C euro18,866.14. At 6 months, health cost was euro32,980.35 in group A, euro28,133.42 in group B, and euro23,629.19 in group C. CONCLUSIONS: MV140 autovaccine and MV140 polybacterial vaccine were more efficient with lower number of UTI at 3 and 6 months and lower health cost along follow-up compared to continued prophylaxis with antibiotics (p < 0.05). Polybacterial MV140 vaccine from collection strain had higher effect to reduce the number of UTI and less health cost than autovaccine.

A proof-of-concept study to investigate the efficacy of heat-inactivated autovaccines in Mycobacterium caprae experimentally challenged goats.

This study aimed to assess the efficacy of a heat-inactivated Mycobacterium caprae (HIMC) vaccine in goats experimentally challenged with the same strain of M. caprae. Twenty-one goats were divided into three groups of seven: vaccinated with heat-inactivated Mycobacterium bovis (HIMB), with HIMC and unvaccinated. At 7 weeks post-vaccination all animals were endobronchially challenged with M. caprae. Blood samples were collected for immunological assays and clinical signs were recorded throughout the experiment. All goats were euthanized at 9 weeks post-challenge. Gross pathological examination, analysis of lung pathology using computed tomography, and bacterial load quantification in pulmonary lymph nodes (LN) by qPCR were carried out. Only HIMC vaccinated goats showed a significant reduction of lung lesions volume and mycobacterial DNA load in LN compared to unvaccinated controls. Both vaccinated groups showed also a significant reduction of the other pathological parameters, an improved clinical outcome and a higher proportion of IFN-γ-producing central memory T cells after vaccination. The results indicated that homologous vaccination of goats with HIMC induced enhanced protection against M. caprae challenge by reducing lung pathology and bacterial load compared to the heterologous vaccine (HIMB). Further large-scale trials are necessary to assess the efficacy of autovaccines under field conditions.

A Focus on Long-Term Follow-Up of Immunoprophylaxis to Recurrent Urinary Tract Infections: 10 Years of Experience with MV140 Vaccine in a Cohort of 1003 Patients Support High Efficacy and Safety.

BACKGROUND: The objective of this article was to assess the long-term efficacy and safety of the MV140 vaccine to prevent recurrent urinary tract infections (UTIs). METHODS: This is a prospective, descriptive, comparative and multicenter study of 1003 patients with 3 or more urinary infections for 12 months, treated with the MV140 vaccine from 2011 to 2021. VARIABLES: Age, gender, urinary infections at 3, 6 and 12 months, distribution according to age and months of the year, smoking, use of MV140 vaccines and autovaccines. RESULTS: Mean age was 78 and 82.7% were women. At baseline, 84.1% had 3 to 5 infections. According to age, 68.6% had >70 years. There were more consultations in March (12.3%) and fewer in August (4.4%). Smokers represented 24.6% and 21.8% follow autovaccines. Results at 3 months: 0 UTI 45%, 1 UTI 31.3%, 2 UTI 19.2%. 6 months: 0 UTI 29.3%, 1 UTI 33.2%, 2 UTI 24.3%. 12 months: 0 UTI 9%, 1 UTI 28.2%, 2 UTI 17.5%. Smokers: 0-1 UTI 80.2% (3 months), 65.5% (6 months), 53.9% (12 months). Non-smokers: 0-1 UTI 85.8% (3 months), 66.8% (6 months), 20% (12 months). p = 0.41, 0.27 and 0.21 respectively. Vaccines: 0-1 UTI 74.5% (3 months), 61% (6 months), 38.8% (12 months). Autovaccines: 0-1 UTI 82.7% (3 months), 68 % (6 months), 28.2% (12 months). p = 0.04, 0.25 and 0.63 respectively. CONCLUSIONS: MV140 reduced the number of UTI to 0-2 in 95.5% at 3 months, 86.8% at 6 months and 54.7% at 12 months. Smoking did not worsen the response of MV140. Autovaccines achieved better results than vaccines only at 3 months. Adverse effects represented 1.49%, but no patient had to abandon treatment.

Characterization of PRRSV in clinical samples and the corresponding cell culture isolates.

Isolation of porcine reproductive and respiratory syndrome virus (PRRSV) in cell culture is a primary means of obtaining virus isolates for autogenous vaccine production and other applications. However, it has not been well characterized whether cell culture isolate and the virus in clinical sample are equivalent. This study compared PRRSV ORF5 sequences from 1024 clinical samples (995 PRRSV-2, 26 PRRSV-1, and three PRRSV-1 and PRRSV-2 PCR-positive) and their isolates in MARC-145 and/or ZMAC cells. For three PRRSV-1 and PRRSV-2 PCR-positive clinical samples, both PRRSV-1 and PRRSV-2 were isolated in ZMAC cells, whereas either PRRSV-1 or PRRSV-2, but not both, was isolated in MARC-145 cells, with isolate sequences matching the respective viruses in clinical samples. Twenty-six PRRSV-1 and most of 995 PRRSV-2 PCR-positive clinical samples had matching viral ORF5 sequences with their cell culture isolates. However, 14 out of 995 PRRSV-2 cases (1.4%) had nonmatching viral sequences between clinical samples and MARC-145 isolates, although viral sequences from clinical samples and ZMAC isolates matched. This is concerning because, if the MARC-145 isolate is directly used for autogenous vaccine production without sequencing confirmation against the virus in the clinical sample, it is possible that the produced autogenous vaccine does not include the desired wild-type virus strain found on the farm and instead contains vaccine-like virus. Vaccine-specific PCR and next-generation sequencing performed on six selected cases indicated presence of ≥2 PRRSV-2 strains (mixed infection) in such clinical samples. In summary, PRRSV ORF5 sequences from clinical samples and cell culture isolates matched each other for majority of the cases. However, PRRSV sequences between clinical sample and MARC-145 cell culture isolate could occasionally be different when the clinical sample contains ≥2 PRRSV-2 strains. Characterizing PRRSV sequences from clinical samples and cell culture isolates should be conducted before using isolates for producing autogenous vaccines or other applications.

A new Montanide™ Seppic IMS1313-adjuvanted autogenous vaccine as a useful emergency tool to resolve a Salmonella enterica subsp. enterica serovar abortus equi abortion outbreak in mares.

Background: In Italy, an autogenous registered vaccine, adjuvanted with aluminum hydroxide, can be administrated to contrast Salmonella enterica subsp. enterica serovar abortus equi infection, coupled to a specific antimicrobial treatment. Case Description: Here, we report the case of an abortion outbreak by Salmonella abortus equi in Central Italy where mares were vaccinated but immediately developed a strong local reaction, maybe due to the adjuvant. Promptly, another autogenous vaccine, substituting the aluminum hydroxide with a new generation adjuvant (Montanide™ Seppic IMS1313), was produced and administrated. The new formulated vaccine did not cause any adverse outcome and conferred high protection titers against the infection. To the best of our knowledge, this is the first reported case of immunization by a vaccine adjuvanted with Montanide™ Seppic IMS1313 in horses. Conclusion: This approach may be used as a preventive strategy for further outbreaks in association with the application of recommended biosafety principles.

Efficacy of passive immunization in broiler chicks via an inactivated Escherichia coli autogenous vaccine administered to broiler breeder hens.

Avian pathogenic Escherichia coli (APEC) cause extra-intestinal infections called colibacillosis, which is the dominant bacterial disease in broilers. To date, given the diversity of APEC strains and the need for an acceptable level of protection in day-old chicks, no satisfactory commercial vaccine is available. As part of a French nationwide project, we selected three representative strains among several hundred APEC that cause colibacillosis disease. We first performed experiments to develop colibacillosis in vivo models, using an inoculum of 3 × 107 CFU of each E. coli strain per chick. Two APEC strains (19-381 and 19-383-M1) were found to be highly virulent for day-old chicks, whereas the third strain (19-385-M1) induced no mortality nor morbidity.We then produced an autogenous vaccine using the (Llyod, 1982; MaCQueen, 1967) 19-381 and 19-383-M1 APEC strains and a passive immunization trial was undertaken. Specific-pathogen-free Leghorn hens were vaccinated twice 2 weeks apart, the control group receiving a saline solution. The vaccinated and control hens exhibited no clinical signs, and egg production and fertility of both groups were similar. Fertile eggs were collected for 2 weeks after the second vaccination and chicks were obtained. After challenge with each APEC (19-381 and 19-383-M1), chicks appeared to be partially protected from infection with the 19-383-M1 strain, with 40% mortality compared with 80% for the non-vaccinated chicks. No protection was found when the chicks were challenged with the 19-381 strain. Now, further work is needed to consider some aspects: severity of the pathogen challenge model, persistence of the protection, number of APEC strains in the autogenous vaccine, choice of adjuvants, and heterologous protection by the vaccine made from strain 19-383-M1.RESEARCH HIGHLIGHTS Three APEC strains were characterized and selected to develop in vivo models of colibacillosis.A bivalent autogenous vaccine was produced and a passive immunization trial was carried out.Protection of chicks was demonstrated when challenged with the 19-383-M1 APEC strain (homologous challenge).Further work is needed in particular to evaluate the protection against heterologous challenge.

Development of autogenous vaccines for farmed European seabass against Aeromonas veronii using zebrafish as a model for efficacy assessment.

Aeromonas veronii bv. sobria is an emerging pathogen for the European seabass cultured in the Aegean Sea (Mediterranean) causing significant problems in the Greek and Turkish aquaculture industry since no licensed vaccine is currently available for the disease. A bivalent vaccine was developed based on two phenotypically distinct strains of the pathogen, PDB (motile, pigment-producing strain) and NS (non-motile, non-pigment-producing). The two strains comprising the bivalent vaccine were evaluated as monovalent products in zebrafish before the seabass trials. Challenges using the homologous or the heterologous strain showed that both vaccines were protective with RPS values ranging between 66 and 100% in zebrafish. The bivalent vaccine was then tested in European seabass following dip or intraperitoneal administration. Efficacy was evaluated separately against both strains comprising the bivalent vaccine. Dip vaccination applied to juvenile seabass of 2.5 g average weight provided protection following challenge tests 30 days post vaccination only in one of the two strains tested (strain PDB, RPS: 88%). This was also the case in the injection vaccination of adult seabass of 60 g average weight where the vaccine was effective only against the PDB strain (RPS: 63%). High antibody titers against both strains were found at 30 and 60 days after intraperitoneal vaccination in the adult seabass. The use of zebrafish as a model for vaccine development for aquaculture species is discussed.

Autogenous vaccines: Quality of production and movement in a common market.

An international meeting, held in Munich, Germany, on 14-16 September 2021, explored the expectations and views of different stakeholders regarding the implementation of the new veterinary medicines Regulation (Regulation (EU) 2019/6) in respect to inactivated autogenous vaccines (AVs) in non-notifiable diseases. Guidance documents on specific Good Manufacturing Practice (GMP) for AVs are scheduled to be developed at EU and a wider international level in the future. Presentations and discussions by the experts from regulatory authorities, industry and users made it apparent that their views on the quality requirements for the starting materials as well as quality standards for premises, personnel and manufacturing were broadly aligned for most of the aspects considered. The conclusions and recommendations of this meeting are expected to facilitate the development of urgently needed guidance documents for a harmonised implementation of this element of the Regulation.

Avian Reoviruses from Clinical Cases of Tenosynovitis: An Overview of Diagnostic Approaches and 10-Year Review of Isolations and Genetic Characterization.

Reoviral-induced tenosynovitis/viral arthritis is an economically significant disease of poultry. Affected birds present with lameness, unilateral or bilateral swollen hock joints or shanks, and/or reluctance to move. In severe cases, rupture of the gastrocnemius or digital flexor tendons may occur, and significant culling may be necessary. Historically, vaccination with a combination of modified live and inactivated vaccines has successfully controlled disease. Proper vaccination reduced vertical transmission and provided maternal-derived antibodies to progeny to protect against disease, at an age when they were most susceptible. Starting in 2011-2012, an increased incidence of tenosynovitis/viral arthritis was observed in chickens and turkeys. In chickens, progeny from reovirus-vaccinated breeders were affected, suggesting commercial vaccines did not provide adequate protection against disease. In turkeys, clinical disease was primarily in males, although females can also be affected. The most significant signs were observed around 14-16 wks of age and include reluctance to move, lameness, and limping on one or both legs. The incidence of tenosynovitis/viral arthritis presently remains high. Reoviruses isolated from clinical cases are genetically and antigenically characterized as variants, meaning they are different from vaccine strains. Characterization of the field isolates reveals multiple new genotypes and serotypes that are significantly different from commercial vaccines and each other. In 2012, a single prevalent virus was isolated from a majority of the cases submitted to the Poultry Diagnostic and Research Center at the University of Georgia. Genetic characterization of the σC protein revealed the early isolates belonged to genetic cluster (GC) 5. Soon after the initial identification of the GC5 variant reovirus, many broiler companies incorporated these isolates from their farms into their autogenous vaccines and continue to do so today. The incidence of GC5 field isolates has decreased significantly, likely because of the widespread use of the isolates in autogenous vaccines. Unfortunately, variant reoviruses belonging to multiple GCs have emerged, despite inclusion of these isolates in autogenous vaccines. In this review, an overview of nomenclature, sample collection, and diagnostic testing will be covered, and a summary of variant reoviruses isolated from clinical cases of tenosynovitis/viral arthritis over the past 10 yrs will be provided.

Estudio recapitulativo- Reovirus aviares de casos clínicos de tenosinovitis: una descripción general de los enfoques de diagnóstico y una revisión de 10 años de aislamientos y caracterización genética. La tenosinovitis/artritis viral inducida por reovirus es una enfermedad económicamente significativa de la avicultura. Las aves afectadas presentan cojera, articulaciones de corvejones o patas inflamadas unilateral o bilateralmente y/o renuencia a moverse. En casos severos, puede ocurrir la ruptura de los tendones del gastrocnemio o del flexor digital, y puede ser necesario una eliminación de aves afectadas significativa. Históricamente, la vacunación con una combinación de vacunas vivas modificadas e inactivadas ha controlado con éxito la enfermedad. La vacunación adecuada redujo la transmisión vertical y proporcionó anticuerpos derivados de las reproductoras a la progenie para protegerlos contra la enfermedad, a una edad en la que eran más susceptibles. A partir de los años 2011-2012, se observó una mayor incidencia de tenosinovitis/artritis viral en pollos y pavos. En los pollos, la progenie de reproductores vacunados con reovirus se vio afectada, lo que sugiere que las vacunas comerciales no brindaron una protección adecuada contra la enfermedad. En pavos, la enfermedad clínica fue principalmente en machos, aunque las hembras también pueden verse afectadas. Los signos más significativos se observaron alrededor de las 14 a 16 semanas de edad e incluyen renuencia a moverse y cojera en una o ambas piernas. La incidencia de tenosinovitis/artritis viral actualmente sigue siendo alta. Los reovirus aislados de casos clínicos se caracterizan genética y antigénicamente como variantes, lo que significa que son diferentes de las cepas vacunales. La caracterización de los aislamientos de campo revela múltiples genotipos y serotipos nuevos que son significativamente diferentes de las vacunas comerciales y entre sí. En 2012, se aisló un solo virus prevalente de la mayoría de los casos presentados al Centro de Investigación y Diagnóstico Avícola de la Universidad de Georgia. La caracterización genética de la proteína sigma C reveló que los primeros aislamientos pertenecían al grupo genético 5 (GC5). Poco después de la identificación inicial de la variante GC5 del reovirus, muchas empresas de pollos de engorde incorporaron estos aislamientos de sus granjas en sus vacunas autógenas y continúan haciéndolo en la actualidad. La incidencia de aislamientos de campo de GC5 ha disminuido significativamente, probablemente debido al uso generalizado de los aislamientos en vacunas autógenas. Desafortunadamente, han surgido variantes de reovirus que pertenecen a múltiples grupos genéticos, a pesar de la inclusión de estos aislados en vacunas autógenas. En esta revisión, se cubrirá una descripción general de la nomenclatura, la recolección de muestras y las pruebas de diagnóstico, y se brindará un resumen de las variantes de reovirus aisladas de casos clínicos de tenosinovitis/artritis viral durante los últimos 10 años.

Evaluation of Pathogenicity and Antigenicity of Avian Reoviruses and Disease Control Through Vaccination.

Avian reoviruses are ubiquitous in poultry production worldwide and can be transmitted vertically or horizontally among chickens. The pathogenicity of reoviruses can range from very pathogenic viruses that affect multiple tissues and organs to apathogenic. Avian reoviruses have been associated with many disease presentations, and two of the most economically significant diseases are viral arthritis/tenosynovitis and viral enteritis. Viral arthritis/tenosynovitis has been recognized since the 1950s and essentially disappeared after development of attenuated live and inactivated vaccines in the 1980s but re-emerged in 2011 due to the emergence of antigenic variants. Viral enteritis was first recognized in the 1970s and became the predominant reovirus-associated disease between 2006 and 2011 due to the emergence of pathogenic enterotropic reoviruses. Pathogenicity of reovirus isolates can be evaluated in several ways, including inoculation of day-old broiler chicks with low maternal reovirus antibody titers via the foot pad route or the oral and intratracheal route. Pathogenic reoviruses induce foot pad inflammation within 3 days of inoculation, and more pathogenic reoviruses are able to disseminate to and damage visceral organs. Only reovirus infections in young chickens result in disease due to age-related resistance to disease development. Reoviruses exist as many serotypes and subtypes with various degrees of interrelatedness. The earliest reovirus strains in the United States were antigenically related to each other and are referred to as S1133-like viruses, but in the 2000s, reoviruses emerged that were antigenically different from the S1133-like viruses. Virus neutralization assay using polyclonal antisera has been used to classify the emerging variant reoviruses into serogroups. The first reovirus vaccines were developed in the 1970s, and by the 1980s breeder vaccination programs were established that protected breeders, prevented vertical transmission of reovirus, and provided maternal immunity to the progeny during the crucial first 3 wk of life. With the emergence of antigenic variant reoviruses in the 2000s, vaccination programs using S1133-like vaccines became ineffective. The poultry industry has relied on vaccination with autogenous inactivated reovirus vaccines to alleviate losses due to viral arthritis/tenosynovitis and viral enteritis. Virus isolates used for autogenous vaccines must be updated regularly and are selected based on pathotype, serotype, or Sigma C (σC) genotype. Live attenuated S1133 vaccines are still used in breeder chickens for the priming effect, followed by one or more injections of the inactivated licensed and/or autogenous vaccines. The route of vaccination and the number of doses received by breeder chickens are very important for a sufficient antibody response. Intramuscular vaccination with inactivated vaccines elicits the highest antibody response, while subcutaneous vaccination with inactivated vaccines elicits a low antibody response. More recently, research has focused on development of alternative vaccines and vaccination strategies. An inactivated variant reovirus vaccine was developed that elicits protection against multiple variant serotypes, and experimental recombinant and subunit vaccines have been described and show potential. More research needs to be done to develop better vaccines, vaccination programs, and other control measures for preventing reovirus infection, transmission, and losses due to disease.

Estudio recapitulativo- Evaluación de patogenicidad y antigenicidad de reovirus aviares y control de enfermedades mediante vacunación Los reovirus aviares son ubicuos en la producción avícola en todo el mundo y pueden transmitirse por vías vertical u horizontal entre los pollos. La patogenicidad de los reovirus puede variar desde virus muy patógenos que afectan múltiples tejidos y órganos hasta virus apatógenos. Los reovirus aviares se han asociado con muchas presentaciones de enfermedades, y dos de las enfermedades más significativas desde el punto de vista económico son la artritis/tenosinovitis viral y la enteritis viral. La artritis/tenosinovitis viral se ha reconocido desde la década de 1950 y esencialmente desapareció después del desarrollo de vacunas vivas atenuadas e inactivadas en la década de 1980, pero resurgió en 2011 debido a la aparición de variantes antigénicas. La enteritis viral se reconoció por primera vez en la década de 1970 y se convirtió en la enfermedad predominante asociada a reovirus entre 2006 y 2011 debido a la aparición de reovirus enterotrópicos patógenos. La patogenicidad de los aislados de reovirus se puede evaluar de varias maneras, incluida la inoculación de pollos de engorde de un día con títulos bajos de anticuerpos maternos contra el reovirus a través de la vía del cojinete almohadilla plantar o la vía oral e intratraqueal. Los reovirus patógenos inducen la inflamación de las almohadillas de las patas dentro de los tres días posteriores a la inoculación, y más reovirus patógenos pueden diseminarse y dañar los órganos viscerales. Solo las infecciones por reovirus en pollos jóvenes resultan en enfermedades debido a la resistencia relacionada con la edad al desarrollo de la enfermedad. Los reovirus existen como muchos serotipos y subtipos con varios grados de interrelación. Las primeras cepas de reovirus en los Estados Unidos estaban relacionadas antigénicamente entre sí y se conocen como virus relacionados a la cepa S1133, pero en la década de 2000 surgieron reovirus que eran antigénicamente diferentes de los virus relacionados con S1133. Se ha utilizado el ensayo de neutralización de virus con antisueros policlonales para clasificar las variantes de reovirus emergentes en serogrupos. Las primeras vacunas contra el reovirus se desarrollaron en la década de 1970, y en la década de 1980 se establecieron programas de vacunación para reproductores que protegían a los reproductores, prevenían la transmisión vertical de reovirus y proporcionaban inmunidad materna a la progenie durante las cruciales primeras tres semanas de vida. Con la aparición de variantes antigénicas de reovirus en la década de 2000, los programas de vacunación con vacunas relacionadas con la cepa S1133 se volvieron ineficaces. La industria avícola se ha basado en la vacunación con vacunas autógenas de reovirus inactivado para aliviar las pérdidas debidas a artritis/tenosinovitis viral y enteritis viral. Los aislados de virus utilizados para las vacunas autógenas deben actualizarse con regularidad y se seleccionan según el patotipo, el serotipo o el genotipo Sigma C (σC). Las vacunas vivas atenuadas S1133 todavía se usan en pollos reproductores para el efecto de preparación, seguidas de una o más inyecciones de las vacunas inactivadas autorizadas y/o autógenas. La vía de vacunación y el número de dosis recibidas por los pollos reproductores son muy importantes para una respuesta de anticuerpos suficiente. La vacunación intramuscular con vacunas inactivadas provoca la mayor respuesta de anticuerpos, mientras que la vacunación subcutánea con vacunas inactivadas provoca una baja respuesta de anticuerpos. Más recientemente, la investigación se ha centrado en el desarrollo de vacunas alternativas y estrategias de vacunación. Se desarrolló una vacuna de reovirus variante inactivada que provoca protección contra múltiples serotipos variantes, y se han descrito vacunas experimentales recombinantes y de subunidades que muestran potencial. Se necesita más investigación para desarrollar mejores vacunas, programas de vacunación y otras medidas de control para prevenir la infección, transmisión y pérdidas por reovirus debido a la enfermedad.

Longitudinal study on the effect of autogenous vaccine application on the sequence type and virulence profiles of Escherichia coli in broiler breeder flocks.

Colibacillosis is one of the most common problems in the poultry industry. Escherichia coli strains on farms are often genetically diverse and therefore commercial vaccines provide little protection to the flocks. Here, we investigated the effect of the autogenous E. coli vaccines on the prevalence of 84 virulence-associated genes in E. coli isolated from four and five consecutive flocks on two broiler breeder farms, respectively. 115 E. coli isolates were sequenced using Illumina technologies, and compared based on both their set of housekeeping genes and their virulence profiles, defined through the composition of virulence genes. Predominantly, phylogenetic analysis showed obvious distinction between the isolates originating from different farms suggesting spatial-dependent transmission of pathogenic strains. We detected 23 sequence types, while 52.58 % of the isolates belonged to two clonal complexes. Analysis of the virulence genes showed highest prevalence (>85 %) of feoB, uspA, uspB, uspG, uspE, fimH, ompA, astA, focA, hlyE, uspC, crl, csgA, ompT and iss, of which 50 % are toxin associated genes, demonstrating the importance of competition in the pathogenesis process. Interestingly, usp genes, which are primarily associated with uropathogenic E. coli strains, were detected in all investigated isolates. The heatmap analysis demonstrated that strains belonging to same phylogenetic groups often share similar virulence profiles, confirming the usefulness of quick tests for phylogenetic typing. However, our results suggest the need to update the list of the minimal predictors used for the identification of avian pathogenic strains. Overall results indicate that continuous application of autogenous vaccines led to lower genetic diversity of E. coli housekeeping genes, but not virulence genes.

Phylogenetic characterization of avian pathogenic Escherichia coli strains longitudinally isolated from broiler breeder flocks vaccinated with autogenous vaccine.

Escherichia coli is the most common bacterial cause of infections in poultry farms. It is known for its genetic heterogenicity that complicates the protection of poultry health through immunoprophylaxis. In farms with continuous problems with colibacillosis, autogenous E. coli vaccine was implemented to the vaccination program instead of commercial vaccines. In this study, we investigated the effect of the autogenous vaccine on E. coli phylogroup diversity on 2 broiler breeder farms with 4 and 5 flocks, respectively. The first flocks on both farms were vaccinated with commercial vaccines, while application of autogenous vaccine was introduced in the second flock on both farms. In total, 113 strains were selected based on the target organs and age of chickens. Targeted organs were the peritoneum, liver, oviduct, and bone marrow, and analyzed strains were isolated from chickens older than 21 wk of age when problems with colibacillosis start emerging. The strains were phylotyped by PCR and allocated to phylogroups A, B1, B2, C, D, E, F or clades I-V. The results showed that autogenous vaccine could significantly affect the phylogroup shift of the strains. On farm A, application of the autogenous vaccine induced significantly lower prevalence (P = 0.01) of the phylogroups represented in the vaccine among the strains later isolated from the vaccinated flock, while on farm B, the results showed a decrease in the phylogenetic diversity with a dominant prevalence of group B2 despite the vaccine application. The results indicate that implementation of the autogenous vaccine can repress the majority of the strains, but also be unable to eliminate the presence of certain phylogroups, and thus lead to strain shift. Further detailed analyses of multilocus sequence typing and virulence genes will elucidate the pathogenic potential and selection of certain strains, with emphasis on B2 phylogroup.

Immunogenicity study of a Streptococcus suis autogenous vaccine in preparturient sows and evaluation of passive maternal immunity in piglets.

BACKGROUND: Streptococcus suis is an important pathogen that causes severe diseases mostly in weaned piglets. Only available vaccines in the field are those composed of killed bacteria (bacterins) but data about their effectiveness are missing. We report here a field study on the immunological response induced by an autogenous vaccine applied in pre-parturient sows. Using a farm with recurrent S. suis serotype 7 problems, the study was divided in three experiments: (I) Sows received the vaccine at 7 and 3 weeks pre-farrowing. (II) Replacement gilts introduced to the herd received the vaccine at 4 and 7 weeks after their entry in quarantine and a boost 3 weeks pre-farrowing. (III) Gilts from experiment II received another boost 3 weeks pre-farrowing at their 3rd/4th parity. Levels, isotype profile and opsonophagocytosis capacity of the serum antibodies induced by vaccination were evaluated in sows and maternal immunity in piglets. RESULTS: In sows (I), the vaccine induced a slight, albeit significant, increase in anti-S. suis total antibodies after 2 doses when compare to basal levels already present in the animals. These antibodies showed a high opsonic capacity in vitro, highlighting their potential protective capacity. A gilt vaccination program of 3 doses (II) resulted in a significant increase in anti-S. suis total antibodies. Levels of maternal immunity transferred to piglets were high at 7 days of age, but rapidly decreased by 18 days of age. A gilt vaccination program ensued a higher transfer of maternal immunity in piglets compared to control animals; nevertheless duration was not improved at 18 day-old piglets. The vaccine response in both gilts and sows was mainly composed of IgG1 subclass, which was also the main Ig transferred to piglets. IgG2 subclass was also found in piglets, but its level was not increased by vaccination. Finally, a recall IgG1 response was induced by another boost vaccination at 3rd/4th parity (III), indicating that the vaccine induced the establishment of a lasting memory response in the herd. CONCLUSIONS: Overall, an optimal gilt/sow vaccination program might result in increased antibody responses; nevertheless duration of maternal immunity would not last long enough to protect post-weaned piglets.