Resposta sorológica aos herpesvirus bovino tipos 1 e 5 e vírus da diarreia viral bovina induzida por vacinas comerciais

Abstract

RESUMO 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 (6/10, GMT 4,0 6/10, GMT 5,6 e 4/10, GMT 1,8 ABSTRACT 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 . 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

Influência da vacinação materna na transferência de imunidade passiva contra as viroses respiratórias dos bovinos

“…No Brasil, é permitida apenas a comercialização de vacinas inativadas para BVDV, entretanto a maioria desses produtos não induz resposta imune humoral consistente (Anziliero et al, 2015). A maior diferença entre a resposta imune aos antígenos vivos modificados e inativados está atrelada à inabilidade de o antígeno morto replicar-se nas células do hospedeiro e induzir resposta imune citotóxica (Th1) mediada pelos linfócitos T CD8 + (Platt et al, 2008;Seder e Hill, 2000).…”

“…Gatti et al (2010) (Anziliero et al, 2015). A cepa de BoHV-1 vivo modificado termossensível replicase apenas em temperaturas inferiores (30-33ºC) ao corpo (37ºC), o que evita o desenvolvimento de infecções sistêmicas (Patterson et al, 2012).…”

Clinical and virological characteristics of calves experimentally infected with a Brazilian isolate of bovine viral diarrhea virus type 1a

“…This difference in titer is due to antigen diversity and is routinely observed in serological cross reactivity tests (BOTTON et al, 1998). A comparatively larger difference in reactivity or titer is observed when samples are tested against a different virus species (BOTTON et al, 1998), and this characteristic is important in routine diagnostic testing and for assessing the effectiveness of vaccines (FLORES et al, 2005;ANZILIERO et al, 2015). Sera from all infected animals collected on days 14 and 42 pi were tested for the presence of anti-p80 antibodies by ELISA.…”

“…Fetal infection is controlled by preventing pregnant cows from coming into contact with the virus or by vaccine immunization (BOLIN, 1995). Most of the BVDV vaccines available in Brazil use type 1 and/or 2 viruses with questionable immunogenicity (ANZILIERO et al, 2015). Importantly, a study showed that PI and transitorily infected animals were still present in vaccinated herds, indicating that vaccination alone is insufficient for eliminating infection (DEZEN et al, 2013).…”

“…In Brazil, there are eight commercial vaccines for BVDV and all of them use inactivated strains of BVDV-1 and/ or BVDV-2. However, BVDV vaccination protects only a relatively small portion of the herd, and in many cases, it is not given systematically (FLORES et al, 2005;ANZILIERO et al, 2015). Therefore, the present study aimed to evaluate the pathogenicity of the Brazilian BVDV 241.10 isolate, classified as BVDV-1a, in calves.…”