Evaluation of Clinical Course of Gamma (P.1) Variant of Concern versus Lineages in Hospitalized Patients with COVID-19 in a Reference Center in Brazil.

The SARS-CoV-2 variant of concern (VOC) gamma (P.1) has increased transmissibility and resulted in elevated hospitalization and mortality rates in Brazil. We investigated the clinical course of COVID-19 caused by gamma and non-VOCs at a reference hospital in Brazil in a retrospective cohort study with nonelderly hospitalized patients from two periods, before and after the emergence of gamma. Cohort 1 included patients from both periods whose samples would be eligible for whole-genome sequencing (WGS). Cohort 2 was composed of randomly selected patients from Cohort 1 whose samples were submitted to WGS. A total of 433 patients composed Cohort 1: 259 from the first and 174 from the second period. Baseline characteristics were similar, except for a higher incidence of severe distress respiratory syndrome at admission in patients from the second period. Patients from the second period had significantly higher incidence rates of advanced respiratory support (adjusted hazard ratio [aHR]: 2.04; 95% confidence interval [CI], 1.60-2.59), invasive ventilatory support (aHR: 2.72; 95% CI: 2.05-3.62), and 28-day mortality from the onset of symptoms (aHR: 2.62; 95% CI: 1.46-4.72). A total of 86 (43 gamma and 43 non-gamma) patients composed Cohort 2. Patients with confirmed gamma VOC infections had higher advanced ventilatory support and mortality rates than non-gamma-infected patients. Our study suggests that non-elderly patients hospitalized for COVID-19 in the second period (used as a proxy of gamma infection) had a more severe clinical course. This might have contributed to higher hospitalization and death rates observed in the second wave in Brazil.

Genomic Surveillance of SARS-CoV-2 Lineages Indicates Early Circulation of P.1 (Gamma) Variant of Concern in Southern Brazil.

The SARS-CoV-2 P.1 lineage emerged in Amazonas (AM), North Brazil and its evolution has been dynamically reported associated with increased transmissibility and/or immune evasion. Here, we evaluated the lineages circulating in 29 cities in Rio Grande do Sul (RS), Southern Brazil between March 2020 and May 2021 and investigated the genetic events associated with the emergence of the P.1. A total of 202 oro/nasopharyngeal SARS-CoV-2 specimens from patients during routine hospital care were submitted to whole-genome sequencing. Phylogenetic and Bayesian Evolutionary Analyses of the P.1 lineage were carried out to determine the relationship between sequences from RS and AM and dated their common ancestor and origin. One hundred six (53%) sequences were assigned as P.1 and most carried the 22 lineage-defining mutations. All the P.1 sequences included other important mutations, such as P314L and R203K/G204R, and revealed a high genetic diversity in the phylogenetic tree. The time-scaled inference suggests that the oldest P.1 sequences from different Brazilian states share a ancestor with those from AM, but the origin of some sequences from RS is unknown. Further, the common ancestor of sequences from RS is dated to mid-June/July 2020, earlier than those previously reported from AM. Our results demonstrate that there is a high degree of genetic diversity among P.1 sequences, which suggests a continuous evolution and community spread of the virus. Although the first P.1 outbreak was reported in AM, the lineage was associated with multiple introductory events and had already been circulating in Southern Brazil prior to November 2020. IMPORTANCE The SARS-CoV-2 P.1 lineage is associated with increased transmissibility and/or immune evasion and presents a dynamic evolution in Brazil. The significance of our research relies in the fact that we evaluated the SARS-CoV-2 lineages circulating in Southern Brazil between March 2020 and May 2021. This evaluation allowed us to detect the genetic events associated with the emergence of the P.1 and its sublineages. This study is important because we were able to establish that the common ancestor of P.1 sequences from Rio Grande do Sul, Southern Brazil, is dated of mid-June/July 2020, earlier than the P.1 sequences previously reported from Amazonas (AM) state. Noteworthy, the high degree of genetic diversity among P.1 sequences found in this study suggests a continuous evolution and community spread of the virus. Moreover, the oldest P.1 sequences from different Brazilian states share a ancestor with those from AM.

Detection of SARS-CoV-2 lineage P.1 in patients from a region with exponentially increasing hospitalisation rate, February 2021, Rio Grande do Sul, Southern Brazil.

The emergence of SARS-CoV-2 P.1 lineage coincided with a surge in hospitalisations in the North region of Brazil. In the South region's Rio Grande do Sul state, severe COVID-19 case numbers rose 3.8 fold in February 2021. During that month, at a COVID-19 referral hospital in this state, whole-genome sequencing of a subset of cases' specimens (n = 27) revealed P.1 lineage SARS-CoV-2 in most (n = 24). Findings raise concerns regarding a possible association between lineage P.1 and rapid case and hospitalisation increases.

Sequence analysis of the DA domain of glycoprotein E2 of pestiviruses isolated from beef cattle in Southern Brazil.

The envelope glycoprotein E2 of pestiviruses is a major target for neutralizing antibodies. In this study, we analyzed the E2 DA domain of 43 pestiviruses from Southern Brazil. The isolates were identified as Bovine viral diarrhea virus (BVDV) subtypes 1a and 1b or BVDV-2b. Compared to reference strains, the BVDV-1 and -2 isolates had four and two mutations in the DA domain, respectively. All BVDV-2 isolates had a deletion of residues 724 and 725. All mutated amino acids in the BVDV isolates had the same aa substitution, and all were in previously identified antibody binding sites. It is possible that an immunity-mediated selection is acting on the pestiviruses circulating in Southern Brazil.

Black queen cell virus and Nosema ceranae coinfection in Africanized honey bees from southern Brazil / Coinfecção por vírus da realeira negra (BQCV) e Nosema ceranae em abelhas africanizadas no sul do Brasil

Bees are fundamental in several aspects, especially in relation to plant biodiversity and pollination. Recently, immense losses are being faced in the number of Brazilian colonies, mainly in southern states of the country, which has a strong beekeeping activity. There are indications that, among the reasons for the losses, pathogens that affect the health of bees may be involved. Among them, the microsporidium Nosema and the black queen cell virus (BQCV) stand out for their prevalence. In this study, 92 colonies of 17 apiaries from southern Brazil were evaluated for infection by Nosema ceranae, Nosema apis and BQCV. Nucleic acid extractions and cDNA synthesis were performed from adult bee samples, followed by Reverse Transcription Polymerase Chain Reaction (RT-PCR) and multiplex PCR. Eight BQCV positive samples were subjected to sequencing. The results showed that N. ceranae and BQCV are circulating in the Southern region of the country, which may be the reason for the loss of colonies. N. apis was not found. N. ceranae was found in 57.6% (53/92) of the colonies and BQCV in 32.6% (30/92). Co-infection was found in 25% (23/92) of the colonies studied, a factor that is suggested to be reducing the hosts' longevity due to the synergistic action of the pathogens. The samples submitted to sequencing indicated similarity of 96.8 to 100% between them, in addition to strong similarity with sequences from Asia, United States, Germany and Peru. This study reports the circulation of N. ceranae and BQCV in apiaries in southern Brazil, in addition to being the first phylogenetic analysis of the Brazilian BQCV sequence.(AU)

As abelhas mostram-se fundamentais em diversos aspectos, especialmente com relação à biodiversidade de plantas e polinização. Recentemente, estão sendo enfrentadas imensas perdas no número de colônias brasileiras, principalmente nos estados do sul do país, com forte atividade apícola. Há indicativos de que, dentre as razões para as perdas, possam estar envolvidos patógenos que afetam a saúde das abelhas. Dentre eles, o microsporídio Nosema e o vírus da realeira negra (BQCV) destacam-se pela prevalência. Neste estudo, foram avaliadas 92 colônias, de 17 apiários do sul do Brasil, a respeito da infecção por Nosema ceranae, Nosema apis e BQCV. Foram realizadas extrações de ácidos nucleicos e síntese de cDNA a partir de amostras de abelhas adultas, seguidos de Reação em Cadeia da Polimerase-Transcriptase Reversa (RT-PCR). Oito amostras positivas para BQCV foram submetidas a sequenciamento. Os resultados mostraram que N. ceranae e BQCV estão circulando na região sul do país, podendo ser a razão para as perdas de colônias. N. apis não foi encontrado. N. ceranae foi encontrado em 57.6% (53/92) das colônias e BQCV em 32.6% (30/92). Foi encontrada coinfecção por ambos em 25% (23/92) das colônias estudadas, fator que sugere a diminuição da longevidade do hospedeiro por ação sinérgica dos patógenos. As amostras submetidas ao sequenciamento indicaram similaridade de 96.8 a 100% entre elas, além de forte similaridade com sequências da Ásia, Estados Unidos, Alemanha e Peru. Este estudo relata a circulação de N. ceranae e BQCV nos apiários do sul do Brasil, além de ser a primeira análise filogenética da sequência do BQCV brasileiro.(AU)

High occurrence of felid alphaherpesvirus 1 and feline calicivirus in domestic cats from southern Brazil / Alta ocorrência de alphaherpesvirus felideo e calicivirus felino em gatos domésticos no Sul do Brasil

Felid alphaherpesvirus 1 (FeHV-1) and feline calicivirus (FCV) affect cats worldwide. The aim of this study was to evaluate the frequency of occurrence of FeHV-1 and FCV in cats with clinical signs of respiratory, oral and/or ocular disease. Samples were collected from cats cared for in veterinary ambulatory and clinics and submitted to molecular detection and viral isolation. Of the 49 cats evaluated, 45 (92%) were positive for at least one of the viruses; 82% (40/49) were positive for FeHV-1 and 41% (20/49) for FCV. Of these, 31% (15/49) were coinfection cases. For FeHV-1, 45% (18/40) of the cats tested were positive from the collection of eye swab, and the same percentage (9/20) was obtained for the FCV by the oral swab. FeHV-1 and/or FCV were isolated in 35% (17/49) of the samples. The main clinical sign observed was ocular secretion in 71% (35/49) of cats, characterized as mild serous, purulent or serosanguineous, and in some cases associated with ocular injury and marked chemosis. Our findings demonstrate the high occurrence of FeHV-1 and FCV in domestic cats in southern Brazil and indicate that measures should be implemented to improve the diagnostic, prevention and management against of these important diseases.(AU)

Alphaherpesvírus felídeo 1 (FeHV-1) e calicivírus felino (FCV) afetam gatos mundialmente. O objetivo deste estudo foi identificar a frequência de ocorrência de FeHV-1 e FCV em gatos com sinais clínicos de doença respiratória, oral e/ou ocular. Amostras foram coletadas de gatos atendidos em ambulatório e clínicas veterinárias e submetidas à detecção molecular e isolamento viral. Dos 49 gatos avaliados, 45 (92%) foram positivos para ao menos um dos vírus; 82% (40/49) foram positivos para o FeHV-1 e 41% (20/49) para o FCV. Destes, 31% (15/49) foram casos de coinfecção. Para o FeHV-1, 45% (18/40) dos gatos foram positivos na coleta do swab ocular, e o mesmo percentual (9/20) foi obtido para o FCV a partir do swab oral. FeHV-1 e/ou FCV foram isolados em 35% (17/49) das amostras. O principal sinal clínico observado foi secreção ocular em 71% (35/49) dos gatos, caracterizada como serosa, purulenta ou serossanguinolenta e, em alguns casos, associada à lesão e quemose. Nossos resultados demonstram a alta ocorrência de FeHV-1 e FCV em gatos domésticos na região Sul do Brasil e indicam que devem ser implementadas medidas para melhorar o diagnóstico, a prevenção e o manejo contra essas importantes doenças.(AU)

Identification of Clade E Avipoxvirus in Brazil.

Avian poxvirus (APV) is an enveloped double-stranded DNA virus that affects many domestic and wild birds worldwide. APVs are classified into three clades (A to C), represented by fowlpox (FP) virus (clade A), canarypox virus (clade B), and psittacinepox virus (clade C), although two additional clades (D and E) have been proposed. In this study, a tumorlike skin lesion found in a domestic fowl was submitted for molecular diagnosis of Avipoxvirus by PCR and sequencing. The phylogenetic analysis revealed that the amplified segment of the corelike 4b protein and polymerase genes clustered in clade E. The APVs in clade E were previously reported from outbreaks in Hungary (flock of turkeys) and in Mozambique (layer chickens), associated with a possible vaccine failure to protect against clade E viruses. To our knowledge, this report is the first identification of clade E in this country, providing new information about host range and genetic diversity of APVs in Brazil, and may represent a potential risk of FP disease outbreaks in commercial poultry.

Reporte de caso- Identificación del Avipoxvirus clado E en Brasil. El poxvirus aviar (APV) es un virus de ADN bicatenario envuelto que afecta a muchas aves domésticas y silvestres en todo el mundo. Los poxvirus aviares se clasifican en tres clados (A, B y C), representados por el virus de la viruela aviar (FP) (clado A), el virus de la viruela del canario (clado B) y el virus de la viruela de los psitácidos (clado C), aunque dos clados adicionales (D y E) han sido propuestos. En este estudio, una lesión cutánea similar a un tumor encontrada en una gallina doméstica fue sometida a diagnóstico molecular de Avipoxvirus por PCR y secuenciación. El análisis filogenético reveló que el segmento amplificado de los genes de la proteína del centro 4b y de la polimerasa se agruparon en el clado E. Los poxvirus aviares en el clado E se reportaron previamente de brotes en Hungría (parvada de pavos) y en Mozambique (gallinas de postura), asociados con una posible falla de la vacuna para proteger contra los virus del clado E. De acuerdo con el conocimiento de los autores, este informe es la primera identificación del clado E en este país, brindando nueva información sobre el rango de hospedadores y la diversidad genética de poxvirus aviares en Brasil, y puede representar un riesgo potencial de brotes de viruela aviar en aves comerciales.

Actinobacillosis outbreak in cattle with clinical manifestation of hippopotamus-like face / Actinobacilose em bovinos com manifestação clínica de cara de hipopótamo

Actinobacillosis outbreak with clinical manifestation of hippopotamus-like face observed in a property located in the municipality of Capão do Leão, Southern Brazil, in September 2016, is described. The cattle herd remained for most of the year in rice stubble. When these areas were occupied with new crops, they were transferred to areas where there were small native forests. Three cattle were affected. They presented a volume increase in the nasolabial and maxillary region, and there was also regional lymph node swelling. The evolution of the disease occurred in approximately six months. In tissue fragments collected for culture, Actinobacillus lignieresii was isolated. The diagnosis was based on clinical findings, histopathological evaluation characterized by the presence of piogranulomas with Splendore Hoepli reaction in its center, bacterial isolation, and identification of A. lignieresii by polymerase chain reaction (PRC) and genetic sequencing.(AU)

Descreve-se um surto de actinobacilose com manifestação clínica de cara de hipopótamo diagnosticado em uma propriedade localizada no município do Capão do Leão, Rio Grande do Sul em setembro de 2016. Os bovinos permaneciam durante a maior parte do ano em restevas de arroz e quando as áreas eram ocupadas com novas lavouras eram transferidos para áreas onde havia pequenas matas nativas. Foram afetados três bovinos adultos que apresentavam aumento de volume na região nasolabial e maxilar e havia, também, tumefação dos linfonodos regionais. A evolução da enfermidade era de aproximadamente seis meses. Nos fragmentos coletados para cultura houve isolamento de Actinobacillus lignieresii. O diagnóstico foi baseado nos achados clínicos, na avaliação histopatológica caracterizada pela presença de piogranulomas com reação de Splendori Hoepli no centro, no isolamento bacteriano, identificação de Actinobacillus lignieresii por reação em cadeia da polimerase (PRC) e sequenciamento genético.(AU)

Genetic identification of pestiviruses from beef cattle in Southern Brazil.

Bovine pestiviruses, e.g., bovine viral diarrhea virus types 1 (BVDV-1 or Pestivirus A), BVDV-2 (Pestivirus B), and HoBi-like pestiviruses (HoBiPeV or Pestivirus H), have been shown to circulate in Brazilian cattle in varied proportions. In this study, we identified genetically pestiviruses circulating in beef cattle in Rio Grande do Sul, the southern most Brazilian state. Screening of serum of 15.584 beef calves destined to be export by an antigen capture ELISA and, subsequently, by reverse-transcription polymerase chain reaction (RT-PCR), revealed 135 containing pestivirus RNA. Genetic typing of these viruses based on nucleotide sequencing and phylogenetic analysis of the 5' untranslated region (5' UTR) of the viral genome allowed for the identification of 90 different viruses, being 38 BVDV-1 (42.2%), 31 BVDV-2 (34.4%), and 21 HoBiPeV (23.4%). Among BVDV-1, only subtypes BVDV-1a (n = 28, 31.1%) and BVDV-1b (n = 10, 11.1%) were identified. All 31 BVDV-2 isolates belonged to BVDV-2b subtype and the 21 HoBiPeV viruses clustered to subgroup 3a. Thus, this study provides an approximate genetic profile of pestiviruses circulating in beef cattle in a traditional Brazilian beef cattle-raising state.

Detection of bovine pestiviruses in sera of beef calves by a RT-PCR based on a newly designed set of pan-bovine pestivirus primers.

The pestiviruses bovine viral diarrhea virus 1 and 2 (BVDV-1 and -2, respectively) and HoBi-like pestivirus (HoBiPeV) are important pathogens of cattle, and a number of reverse-transcription PCR (RT-PCR)-based assays have been developed for their detection in clinical specimens. We evaluated a newly designed set of pan-bovine pestivirus primers (BP189-389) in a gel-based RT-PCR screening test for pestiviruses in the sera of beef calves destined for export from southern Brazil. Serum samples positive for BVDV antigens by an antigen ELISA ( n = 135) were submitted to RT-PCR assays using different sets of primers, followed by nucleotide sequencing of the amplicons. RT-PCR with pestivirus primers 324-326 detected 110 positive samples: BVDV-1 ( n = 62), BVDV-2 ( n = 38), and HoBiPeV ( n = 10). A PCR using primers HCV90-368 detected 97 positive samples (64 BVDV-1; 33 BVDV-2). An additional RT-PCR round using BVDV-2-specific primers (2F-2R) detected 45 positive samples (including 38 detected by primers 324-326 and 33 by HCV90-368); whereas a RT-PCR using HoBiPeV-specific primers (N2-R5) detected 26 positive samples (including 10 detected by primers 324-326).The assay using the primers BP189-389 detected all 135 ELISA-positive samples, including the 26 HoBiPeV detected by primers N2-R5. Our results demonstrated that primers BP189-389 compare favorably against other primer sets in the detection of bovine pestiviruses, especially HoBiPeV. This conventional PCR may be useful for efficient detection of pestiviruses in bovine sera and other specimens as well, especially in laboratories without real-time PCR equipment.

Viruses that affect Apis mellifera and their occurrence in Brazil / Vírus que acometem Apis mellifera e sua ocorrência no Brasil

ABSTRACT: Bees are very important insects for agriculture, fulfilling an important role in pollination and renewal of the ecosystem. However, in several countries significant losses of colonies and population decline of honeybees and native bees have been reported in recent years. Most researchers reported that premature losses are linked to several factors, including viruses that have a great impact on the colonies. This article reports the identification of new viruses, some transmission routes, the association of these parasites with the symptoms of the diseases that affect the health of honeybees, as well as viruses that have been described in Brazil.

RESUMO: As abelhas são insetos de grande importância na agricultura, cumprindo um papel muito importante na polinização e na renovação do ecossistema. No entanto, em diversos países têm sido relatadas perdas significativas de colônias e declínio da população de abelhas melíferas e nativas, nos últimos anos. Com isso, surgiram novos estudos sobre este assunto. A maioria dos pesquisadores relata que as perdas prematuras estão ligadas a diversos fatores, dentre eles os vírus, que causam grande impacto nas colônias. Este artigo visa expor as novas identificações de vírus, algumas rotas de transmissão, a associação dos mesmos a parasitas e a sintomatologia das enfermidades que afetam a saúde de abelhas melíferas, bem como os vírus que já foram descritos no Brasil.

Detection of respiratory viruses in shelter dogs maintained under varying environmental conditions

Abstract Three dog shelters in Rio Grande do Sul were investigated for associations between the occurrence of respiratory viruses and shelter environmental conditions. Nasal secretions randomly collected during the cold season were tested via PCR, and this data collection was followed by nucleotide sequencing of the amplicons. In shelter #1 (poor sanitary and nutritional conditions, high animal density and constant contact between dogs), 78% (58/74) of the nasal samples were positive, 35% (26/74) of which were in single infections and 44% (32/74) of which were in coinfections. Shelters #2 and #3 had satisfactory sanitary and nutritional conditions, outdoors exercise areas (#2) and animal clustering by groups (#3). In shelter #2, 9% (3/35) of the samples were positive for Canine parainfluenza virus (CPIV), and 6% (2/35) were positive for Canid herpesvirus 1 (CaHV-1). In shelter #3, 9% (7/77) of the samples were positive for Canine adenovirus type 2 (CAdV-2), and 1% (1/77) were positive for Canine distemper virus (CDV). The amplicon sequences (CPIV and CDV nucleoprotein gene; CAdV-2 E3 gene; CaHV-1 glycoprotein B gene) showed 94-100% nucleotide identity with GenBank sequences. Our results demonstrate that CPIV, CAdV-2 and CDV are common in dog shelters and that their frequencies appear to be related with environmental and nutritional conditions. These results indicate the need for control/prevention measures, including vaccination and environmental management, to minimize these infections and improve dog health.

Detection of respiratory viruses in shelter dogs maintained under varying environmental conditions.

Three dog shelters in Rio Grande do Sul were investigated for associations between the occurrence of respiratory viruses and shelter environmental conditions. Nasal secretions randomly collected during the cold season were tested via PCR, and this data collection was followed by nucleotide sequencing of the amplicons. In shelter #1 (poor sanitary and nutritional conditions, high animal density and constant contact between dogs), 78% (58/74) of the nasal samples were positive, 35% (26/74) of which were in single infections and 44% (32/74) of which were in coinfections. Shelters #2 and #3 had satisfactory sanitary and nutritional conditions, outdoors exercise areas (#2) and animal clustering by groups (#3). In shelter #2, 9% (3/35) of the samples were positive for Canine parainfluenza virus (CPIV), and 6% (2/35) were positive for Canid herpesvirus 1 (CaHV-1). In shelter #3, 9% (7/77) of the samples were positive for Canine adenovirus type 2 (CAdV-2), and 1% (1/77) were positive for Canine distemper virus (CDV). The amplicon sequences (CPIV and CDV nucleoprotein gene; CAdV-2 E3 gene; CaHV-1 glycoprotein B gene) showed 94-100% nucleotide identity with GenBank sequences. Our results demonstrate that CPIV, CAdV-2 and CDV are common in dog shelters and that their frequencies appear to be related with environmental and nutritional conditions. These results indicate the need for control/prevention measures, including vaccination and environmental management, to minimize these infections and improve dog health.

Resposta sorológica aos herpesvirus bovino tipos 1 e 5 e vírus da diarreia viral bovina induzida por vacinas comerciais / Serological response to bovine herpesvírus 1 and 5 and bovine viral diarrea virus induced by comercial vaccines

Este trabalho avaliou a imunogenicidade de vacinas para os herpesvírus bovino 1 e 5 (BoHV-1, BoHV-5) e vírus da diarreia viral bovina 1 e 2 (BVDV-1, BVDV-2), disponíveis no mercado brasileiro. Para isso, novilhos de raças de corte foram alocados em grupos de 10-12 animais e vacinados duas vezes, com intervalo de 30 dias, com cada uma das oito vacinas disponíveis. Amostras de soro coletadas 30 dias após a segunda dose foram submetidas ao teste de virusneutralização (VNT), frente a cepas de BoHV-1, BoHV-5, BVDV-1 e BVDV-2. Com exceção de duas vacinas que induziram soroconversão em 8/10 e 9/10 dos animais, as demais induziram anticorpos neutralizantes contra o BoHV-1 em todos os animais vacinados (títulos médios geométricos [GMTs] entre 1,7 e 4,8). Quatro vacina s induziram anticorpos reagentes com o BoHV-5 em todos os animais (GMTs de 1,0 a 4,2), enquanto três vacinas induziram soroconversão parcial em 5/10, 6/10 e 7/10 animais. Apenas uma vacina induziu resposta sorológica detectável frente ao BVDV-1 em todos os animais vacinados (GMT=6,7). Soroconversão parcial ao BVDV-1 foi detectada em quatro grupos vacinais (6/10, GMT 4,0 6/10, GMT 5,6 e 4/10, GMT 1,8). Uma vacina induziu resposta em apenas um animal (título de 40) e três vacinas não induziram anticorpos detectáveis contra o BVDV-1 em nenhum animal. Atividade neutralizante frente ao BVDV-2 foi detectada apenas em três grupos vacinais, e parcialmente (10/10, GMT 6,5; 5/10, GMT 1,6 e 2/10, GMT 1,0). Cinco vacinas não induziram atividade neutralizante detectável frente ao BVDV-2 em nenhum dos animais imunizados. Esses resultados demonstram que o componente BoHV-1 da maioria das vacinas comerciais possui imunogenicidade adequada. No entanto, o componente BVDV da grande maioria das vacinas não induz resposta neutralizante consistente frente ao BVDV-1 e, ...

This study evaluated the immunogenicity of vaccines for bovine herpesvirus 1 and 5 (BoHV-1/5) and viral diarrhea virus 1 and 2 (BVDV-1/2) available in the Brazilian market. Calves were divided into groups (10-12), vaccinated twice with a 30 days interval. Samples collected 30 days after the second dose were submitted to virus neutralization test against BoHV-1, BoHV-5, BVDV-1 and BVDV-2. With the exception of two vaccines that induced seroconversion in 8/10 and 9/10 of the animals, the other induced antibodies against BoHV-1 in all vaccinated animals (geometric mean titers [GMTs] 1.7 and 4.8) and four induced antibodies against BoHV-5 in all animals (GMTs 1.0 to 4.2), whereas three vaccines induced partial seroconversion (5/10, 6/10 and 7/10 animals). Only one vaccine induced antibody response to BVDV-1 in all vaccinated animals (GMT=6.7). Partial seroconversion to BVDV-1 was detected in four vaccine (6/10, GMT 4.0; 6/10, GMT 5.6 and 4/10, GMT 1.8). A vaccine induced response in only one animal and three vaccines did not induce antibodies against BVDV-1 in any animal. Antibodies to BVDV-2 were detected only in three vaccine groups, and partly (10/10, GMT 6.5; 5/10, GMT 1.6 and 2/10, GMT 1.0). Five vaccines did not induce antibodies to BVDV-2 in any of the animals. Results demonstrate that the BoHV-1 component of commercial vaccines seems to have acceptable immunogenicity. However, the BVDV component of most vaccines does not induce consistent response against BVDV-1, especially, to BVDV-2. It is evident that strategies for production of vaccines, particularly to BVDV must be urgently revised.