Passive Immunity Stimulated by Vaccination of Dry Cows with aSalmonellaBacterial Extract

Abstract

BackgroundDiarrhea because of Salmonella infection is a cause of neonatal calf diarrhea. The stimulation of passive immunity in the calf by vaccinating the dam for Salmonella has shown some success in previous studies; however, there are no data on the use of currently licensed vaccines in the United States.ObjectiveTo determine whether vaccinating cows at dry‐off with a commercially available Salmonella bacterial extract would stimulate Salmonella‐specific antibodies in the colostrum of cows at calving and whether these antibodies would be transferred to the calf.AnimalsSixty Holstein cattle and 59 calves from a herd presumed to be naïve to Salmonella.MethodsProspective clinical trial. Thirty cows were vaccinated at dry‐off with a Salmonella enterica serovar Newport bacterial extract and again 4 weeks later. An additional 30 cows received only saline. Calves fed fresh colostrum from their dam within 4 hours of birth had blood collected 24 hours later.ResultsVaccinated cattle had increased Salmonella Newport antibody titers at calving in blood (P = .01) and colostrum (P = .011). Calves that received colostrum from vaccinated cattle also had significant increase in Salmonella antibodies (1.04 ± 0.03) as compared to calves born to unvaccinated cows (0.30 ± 0.02).Conclusions and Clinical ImportanceThe results indicate that the use of a commercially available Salmonella vaccine can stimulate antibodies that are passed on to the calf via colostral transfer. Further studies need to be done to determine whether these antibodies will offer protection against Salmonella challenge.

Salmonella Serogroup C: Current Status of Vaccines and Why They Are Needed

“…This is a subunit component vaccine under conditional license, and it contains purified outer membrane proteins from S. Newport. This vaccine formulation has been shown to induce antibody production in cattle; however, no significant difference in fecal shedding of Salmonella or symptoms of disease were observed between vaccinated and unvaccinated groups (56,57). Surprisingly, it was observed that vaccinated cattle produced more milk than unvaccinated cattle, although the mechanism for this remains unclear (56).…”

Exploratory cohort study to determine if dry cow vaccination with aSalmonellaNewport bacterin can protect dairy calves against oralSalmonellachallenge

“…Administration of a Salmonella Newport siderophore‐receptor and porin (SRP) subunit vaccine per label directions to cows during the dry period can substantially increase the Salmonella ‐specific colostral titers. When fed to calves within the first hours of life, this colostrum led to a significant increase in the calves' Salmonella Newport antibody titers . This finding suggests that dry cow vaccination and subsequent colostrum administration may be a viable method to provide immunity against Salmonella in neonatal calves, potentially decreasing the incidence, severity, and mortality of the infection.…”

“…Serum and colostrum antibody titers for Salmonella Newport were determined as previously described by an ELISA. 8…”

Salmonella in Dairy Cattle

“…It does result in demonstrable antibody levels in colostrum when administered twice during the dry period, although the protective effect of these antibodies against challenge postnatally in calves at this time is unknown. 47 The efficacy of other gram-negative core vaccines to prevent or decrease Salmonella disease, such as the J5 product (Enviracor, Zoetis Animal Health) or Endovac-bovi (Immvac, Columbia, MO), which are specifically marketed for protection against coliform mastitis, is highly debatable.…”

“…There is very little evidence to support effective control of Salmonella infection in calves via passive transfer from immunized dams with any type of vaccine although the siderophore/porin product mentioned in the previous section in adults will stimulate colostral antibody. 47 Salmonella is predominantly cleared by cellular immune responses and humoral antibody alone may not provide satisfactory protection. Vaccine use in calves is best considered when management efforts at control and prevention have already been put in place, or if these have been implemented but found to make little difference in the pattern or severity of disease.…”