Pfizer Animal Health

Bacterin-Toxoid-Vaccine

Bovine Rota-Coronavirus Vaccine, Killed Virus-Clostridium Perfringens Type C-Escherichia Coli Bacterin-Toxoid

U.S. Vet. Lic. No.: 189

Description: SCOURGUARD 3^® (K)/C contains a liquid preparation of inactivated bovine rotavirus and coronavirus propagated on established cell lines, a K99 E. coli bacterin, and Cl. perfringens type C toxoid. The vaccine is adjuvanted to enhance the immune response.

Contains gentamicin and merthiolate as preservatives.

Indications: SCOURGUARD 3^® (K)/C is for vaccination of healthy, pregnant cows as an aid in passive maternal immunization of their calves against neonatal calf diarrhea caused by bovine rotavirus, bovine coronavirus, enterotoxigenic strains of Escherichia coli (E. coli) having the K99 pili adherence factor, and neonatal calf diarrhea caused by Clostridium perfringens (Cl. perfringens) type C (beta) toxin.

Directions:

1. General Directions: Vaccination of healthy, pregnant cows is recommended. Shake well. Aseptically administer 2 mL intramuscularly (IM) only. In accordance with Beef Quality Assurance guidelines, this product should be administered in the muscular region of the neck.

2. Primary Vaccination: Administer 2 IM doses at least 2 weeks apart to pregnant cows, with the second dose given 2-3 weeks before calving. If cows have not calved within 40 days after receiving their last dose, revaccination with a single dose is recommended.

3. Revaccination: Revaccination with a single dose 2-3 weeks before each subsequent calving is recommended.

4. Good animal husbandry and herd health management practices should be employed.

Precaution(s): Store at 2°-7°C. Prolonged exposure to higher temperatures may adversely affect potency. Do not freeze.

Use entire contents when first opened.

Sterilized syringes and needles should be used to administer this vaccine.

Transient temperature increases may occur following vaccination.

Caution(s): As with many vaccines, anaphylaxis may occur after use. Initial antidote of epinephrine is recommended and should be followed with appropriate supportive therapy.

This product has been shown to be efficacious in healthy animals. A protective immune response may not be elicited if animals are incubating an infectious disease, are malnourished or parasitized, are stressed due to shipment or environmental conditions, are otherwise immunocompromised, or the vaccine is not administered in accordance with label directions.

Warning(s): Do not vaccinate within 21 days before slaughter.

For veterinary use only.

Discussion: Disease Description: Neonatal calf diarrhea is a disease of complex origin that can be caused by both viral and bacterial agents. Enterotoxigenic E. coli, rotavirus, and coronavirus are commonly isolated from scouring calves, often in combination with other bacteria or viruses.^1,2 Studies have shown that most enterotoxigenic E. coli strains isolated from scouring calves have K99 pili, antigenic structures which facilitate colonization of the gut lining.^3,4 Enterotoxins produced by those strains, combined with intestinal cell damage by rotavirus and coronavirus, cause secretion of body fluids and electrolytes into the gut. Such fluid loss produces a severe diarrhea, which results in dehydration, electrolyte imbalance, and metabolic acidosis. Incidence of calf diarrhea is most frequent and severe within the first 2 weeks of life.^5,6 Hence, a calf's primary source of protection is immediate consumption of colostrum containing high levels of maternal antibodies for effective passive immunization.^7,8

In cattle, infection with Cl. perfringens type C causes severe enteritis, dysentery, and toxemia, as well as high mortality in calves. It can also cause enterotoxemia in adult cattle.

Trial Data: Safety and Efficacy: Immunogenicity tests measuring antibody levels were conducted for all components of SCOURGUARD 3^® (K)/C. Serological response to vaccination in pregnant test cows was compared to that in nonvaccinated control cows. Table 1 shows antibody response in both colostrum and calf serum to Cl. perfringens type C toxoid, when administered as part of the combined vaccine (containing all the antigens in SCOURGUARD 3^® (K)/C).

Table 1. Geometric Mean Antibody Response in Colostrum and Calf Serum to Cl. perfringens Type C (beta) Toxoid in a Polyvalent Vaccine

* Geometric mean levels are antitoxin levels expressed in international units (IU) of antitoxin/mL for both colostrum and calf serum.

The protective level of type C antitoxin for cattle has not been determined experimentally, but a level of 0.10 to 0.15 IU/mL for both colostrum and serum has been determined to be protective in sheep,⁹ and that level is generally considered protective in cattle as well. Type C antitoxin levels in colostrum and calf serum far exceeding the 0.15 IU/mL level occurred following vaccination, even when calves were born as many as 117 days after the cow received her last vaccine dose.

In immunogenicity studies of the rota-coronavirus vaccine component, the effect of vaccination on colostrum and milk antibody levels was evaluated. Colostrum samples were collected from vaccinated cows on the day of calving. Milk samples were collected from cows at various intervals after calving. Similar samples were collected from nonvaccinated control cows. All samples were tested for antibody levels against rotavirus and coronavirus.

Results presented in Table 2 show antibody levels in both colostrum and milk to rotavirus and coronavirus components of the combined vaccine, which contained all the antigens in SCOURGUARD 3^® (K)/C. The geometric mean antibody levels to rotavirus and coronavirus were significantly greater in vaccinates than in nonvaccinates.

Table 2. Mean Antibody Response in Colostrum and Milk to Rotavirus and Coronavirus in a Polyvalent Vaccine

* Reciprocal geometric mean titers.

Efficacy of the E. coli K99 factor was demonstrated in a controlled challenge-of-immunity study. Pregnant cows that received 2 doses of bacterin provided maternal immunity which fully protected 80% of their calves from virulent challenge. The remaining 20% of calves in that group experienced transient diarrhea lasting less than 48 hours, with no deaths occurring. Conversely, 100% of calves from nonvaccinated cows experienced severe diarrhea resulting in a 58.8% death loss after challenge.

References: Available upon request.

Presentation: 10 dose and 50 dose vials.

75-4858-04

Disclaimer: Every effort has been made to ensure the accuracy of the information published. However, it remains the responsibility of the readers to familiarize themselves with the product information contained on the product label or package insert. Compendium Code No.: 36900640