J-VAC® by Merial - Protects dairy cows from coliform mastitis

Product Description

J-VAC is a broad-spectrum bacterin-toxoid that aids in the prevention of mastitis caused by Escherichia coli and the effects of endotoxemia caused by E. coli and Salmonella Typhimurium. 

It is approved for a whole herd protocol and can be used for lactating cows, heifers or dry cows.

Proven Efficacy for Cows and Heifers

In a field trial with more than 700 cows and heifers, two doses of J-VAC reduced the incidence of clinical coliform mastitis cases by 81 percent.*

Clinical Coliform Mastitis
  • Unvaccinated controls - 20 cases
  • J-VAC group- 4 cases
E. Coli Clinical Coliform Mastitis
(subset of data for the E. coli pathogen)
  • Unvaccinated controls -10 cases
  • J-VAC group - 2 cases


J-VAC is the only vaccine of its kind approved for usage in the whole herd.

Whole Herd Any stage of lactation 2-4 weeks after first dose
Dry Cow Dry-off 1-3 weeks before calving
Heifer 60 days before calving 1-3 weeks before calving

J-VAC has been shown to reduce the incidence of clinical coliform mastitis cases by
J-VAC is easy to administer with a

The unique TandemTM adjuvant in J-VAC keeps antigens in suspension, releasing them over time, and stimulating enhanced immunity.

Features & Benefits

  • Protects cows and heifers against coliform mastitis.
  • Contains TANDEM, a unique polymer-based adjuvant that keeps antigens in suspension, releases them over time, and stimulates enhanced immunity.
  • Can be administered intramuscularly or subcutaneously.
  • Zero milk withhold.

Dosage Information

  • As an aid in the prevention of mastitis, inject 2 mL (one dose) intramuscularly or subcutaneously at seven months of gestation or at dry-off; revaccinate at one to three weeks before calving.
  • As an aid in the prevention of the effects of endotoxemia, whole herd vaccination may be done at any time. Vaccinate with 2 mL (one dose) followed by a second 2 mL dose two to four weeks later.
  • Annual revaccination required.
  • Calves vaccinated under 6 months of age should be revaccinated after reaching 6 months of age.

*Data on file at Merial

Merial is now part of Boehringer lngelheim. Tandem is a trademark, and J-VAC is a registered trademark of Merial. @2018 Boehringer lngelheim Vetmedica, Inc. BOV-1864-BIO1118

Product Resources

Contact Information

  • Boehringer Ingelheim Vetmedica, Inc.

    Cattle Division

    3239 Satellite Blvd NW,
    Duluth, GA 64506

    • Phone 866-638-2226
    • Fax 816-326-9167
    • e-mail