Betty Jo Gigot, Editor and Publisher

The venue was superb and the presentations extensive and informative, but the star of the show was Vista™, a new one-dose, modified-live vaccine from Intervet Inc. Both Paul Casady, area director – Americas, and Intervet, Inc., president Chris Ragland were present for its debut.

The first in a series of regional meetings hosted by Intervet this summer to introduce a new vaccine line was held at the Hotel del Coronado, Coronado, Calif., and drew 40 feedyard consulting veterinarians. Cow-calf and stocker veterinarians and dairy veterinarians were hosted next, as Intervet presented one of the most extensive cattle vaccine industry launches.

Dedicated to research and development
John Hutcheson, Ph.D., of Intervet opened the meeting with background on the development of Vista ™. Intervet, one of the largest vaccine manufactures, is the third-largest animal-health company in the world and the seventh largest in the United States.

Hutcheson stressed the company’s dedication to research and development, with 15 percent of the company’s employees working in that field. Intervet has invested $40 million in their manufacturing, research and distribution facility at DeSoto, Kan., where they own 320 acres and run many of their vaccine tests. The company has 13 other sites where research is conducted.

A full line
The vaccine line is billed as the longest lasting, most complete protection available against Infectious Bovine Rhinotracheitis (IBR), Bovine Viral Diarrhea (BVD) Type 1 and Type 2, Bovine Respiratory Syncytial Virus (BRSV) and Parainfluenza (3) (PI3) with either Pasteurella multocida/Mannheimia haemolytica or Leptospira (including hardjo-bovis) combinations.

“Vista is the only modified-live vaccine with a six-month duration of immunity for IBR and BVD Type 1 and Type 2 on the label,” explained Tom Shelton, DVM, Intervet senior technical services specialist. “This level of protection is complemented with cell-mediated immunity data for BVD Type 1 and Type 2, IBR and BRSV.

“Research indicates the IBR fraction in Vista provides protection from clinical signs of IBR following an IBR challenge 182 days following vaccination. A single dose of Vista also is proven to protect calves for 183 days post vaccination from BVD Type 1, as well as the highly virulent BVD Type 2 strain responsible for the severely devastating outbreaks in 1993 in the eastern regions of the United States and Canada.”

Shelton pointed out that Vista is compliant with Beef Quality Assurance recommendations. The primary vaccination consists of a single, 2-mL dose administered subcutaneously (SQ) in the neck. Subcutaneous administration, when compared to vaccines administered IM, has been found to elicit a more favorable immune response that provides for optimal initial response to a vaccine.

Other variations include the industry’s only 100-dose presentation for Vista 3 SQ and Vista 5 SQ and one-dose BRSV.

Traditional modified-live mixing procedures call for adding the entire diluent solution into the freeze-dried cake bottle. A new mixing procedure for the 50- and 100-dose presentations calls for rehydrating the freeze-dried cake bottle with part of the accompanying bottle of sterile or bacterin diluent using a sterile transfer needle provided in the package.

Cell-mediated immunity
James Roth, DVM, Iowa State University, presented cell-mediated immunity (CMI) results of tests conducted at ISU. Roth discussed the newly found ability of measuring CMI in the laboratory and his group’s conclusions from tests they had run on Vista.

Conclusions post-vaccination included: (1) One dose of multivalent modified-live virus Vista vaccine induced significant increases in CMI responses to all 4 tested viruses (IBR, BVD Type 1 and Type 2, and BRSV); (2) Specific CMI responses to 4 tested viruses by CD25-expressing cells remained significantly higher than the control group up to the pre-challenge date; (3) Specific CMI responses to 4 tested viruses by IFNy-expressing cells were significantly higher than control group between 4 and 8 weeks post-vaccination, then declined afterward.

Conclusions post-challenge included: (1) The vaccinated group showed anamnestic antibody and CMI responses to challenge virus (BHV-1) as early as one week post-challenge; (2) The control group did not show specific CMI responses to challenge virus until two weeks post-challenge; (3) The vaccinated group shed significantly less virus in nasal secretion for a shorter period of time.

Intervet was especially proud of the large amount of data that had been gathered to bring the new Vista line to market.

“This is what we do. The cattle business is the core of our company, as is agriculture. We will remain a company heavily invested in research and development of products for the cattle industry. We will let our actions speak for themselves,” Chris Ragland said.