Serological response against bovine herpesvirus and bovine viral diarrhea virus induced by commercial vaccines in Holstein heifers

Abstract

Vaccination is a strategy to the prevention and control of reproductive diseases caused by bovine viral diarrhea virus (BVDV) and bovine herpesvirus type 1 (BoHV-1), however the various compositions of commercial vaccines should be evaluated for their ability to induce protection mediated by antibodies. The objective of this research was to evaluate the production of specific neutralizing Abs against BVDV-1 and 2, and BoHV-1 induced by commercial vaccines composed by different adjuvants. Holstein heifers were vaccinated and distributed in three experimental groups: Group I (G1) was vaccinated with a commercial vaccine containing inactivated BVDV-1, BVDV-2 and BoHV-1 diluted in alum hydroxide as adjuvant (n=9); Group II (G2) was vaccinated with an product containing inactivated strains of BVDV-1, BVDV-2, BoHV-1 and BoHV-5 diluted in oil emulsion as adjuvant (n=10); Group III (G3) was vaccinated with a commercial vaccine containing inactivated BVDV-1 and BVDV-2, besides live modified thermosensitive BoHV-1, diluted in Quil A, amphigen and cholesterol (n=10); A control, non-vaccinated group (n=6) was mock vaccinated with saline. Heifers received two subcutaneous doses of 5mL of each commercial vaccine on the right side of the neck, with 21 days interval. Humoral immune response was assessed by the virus neutralization test (VN) against BVDV-1 (NADL and Singer strains), BVDV-2 (SV253 strain) and BoHV-1 (Los Angeles strain) in serum samples collected on vaccination days zero (D0), 21 (D21) and 42 (D42; 21 days after boosting). Neutralizing Abs against BVDV-1 NADL was detected only in D42, regardless of the vaccine used. Similar geometric mean titers (GMT) for BVDV-1 NADL were observed between G1 (log2=5.1) and G3 (log2=5.1). The seroconversion rate (%) was higher in G1 (78%) when compared to G2 (10%) and G3 (40%). For BVDV-1 Singer, it was also possible to detect Abs production in G1 (log2=5.8, 100% seroconversion rate) and G3 (log2=3.5, seroconversion rate = 60%), only after the booster dose (D42). Neutralizing Abs to BVDV-2 (SV253) were detected only in G3, observing 90% seroconversion associated with high titers of Abs (log2=6.7) after the 2nd dose of vaccine (D42). Heifers from G1 and G3 responded to BoHV-1 after the first dose (D21): G1 (log2=2.5, seroconversion rate = 67%) and G3 (log2=0.7, seroconversion rate = 80%). In D42, a higher magnitude response was observed in the heifers from G3 (log2=6.1, 100%) compared with G1 (log2=4.3, 100%) and G2 (log2=2.7, 60%). Based on the data obtained, it can be concluded that the commercial vaccine contained aluminum hydroxide (G1) was most effective in the induction of antibodies against BVDV-1. On the other hand, this vaccine did not induce the production of neutralizing Abs against BVDV-2. Only the heifers from G3 (Quil A, amphigen and cholesterol) generated neutralizing Abs against BVDV-2. The animals that received commercial vaccine containing oil emulsion as adjuvant (G2) had a weak/undetectable response against BVDV-1 and BVDV-2. The best protective response against BoHV-1 was observed in heifers vaccinated with the live modified thermosensitive virus.

About the necessity of including HoBi-like pestiviruses in bovine respiratory and reproductive viral vacines

“…This has been demonstrated in our study, in which commercial and experimental BVDV-1/ BVDV-2 vaccines showed variable levels of neutralization against HoBiPeV. Nonetheless, a number of studies from our group have shown that commercial vaccines do not usually induce such high VN levels upon the recommended protocol of two-doses (Vogel et al 2001, 2002, Lima et al 2005, Anziliero et al 2015, Baccili et al 2019, Dotto 2020). Thus, is conceivable that the response to vaccination with current BVDV-containing commercial vaccines would not result in protective cross-neutralization titers to HoBiPeV isolates.…”

Field Evaluation of Commercial Vaccines against Infectious Bovine Rhinotracheitis (Ibr) Virus Using Different Immunization Protocols

“…Recently, other researchers have analyzed the serological response against BoHV-1 by comparing live vaccines (MLV) and inactivated vaccines [ 23 , 24 ]. The best protective response was observed in heifers vaccinated with live modified thermosensitive virus [ 24 ]. However, in a meta-analysis where the prevention of abortion in cattle following vaccination against BoHV-1 was reviewed, it was found that both MLV and inactivated vaccines decrease abortion risk.…”

“…Recently, other researchers have analyzed the serological response against BoHV-1 by comparing live vaccines (MLV) and inactivated vaccines [23,24]. The best protective response was observed in heifers vaccinated with live modified thermosensitive virus [24].…”