Skip to Content

The originating document has been archived. We cannot confirm the completeness, accuracy and currency of the content.


This page contains information on EWTF for veterinary use.
The information provided typically includes the following:
  • EWTF Indications
  • Warnings and cautions for EWTF
  • Direction and dosage information for EWTF


This treatment applies to the following species:
Manufacturer: Intervet/Merck Animal Health

Encephalomyelitis-influenza Vaccine, Eastern And Western, Killed Virus, Tetanus Toxoid

Directions For Use

Please Read Carefully


EWTF™ is a polyvalent product recommended for the vaccination of healthy equines against eastern and western equine encephalomyelitis, equine influenza due to types A1 and A2 viruses, and tetanus. The inactivated antigen fractions are purified and concentrated using the latest ultrafiltration techniques. The antigens are combined in a carefully standardized and balanced manner to ensure compatibility and consistency. Special adjuvant components are utilized to enhance the immune response to the antigens.

EWTF Indications

EWTF™ is recommended for vaccination of healthy equines against eastern and western equine encephalomyelitis and tetanus, and as an aid in the prevention of equine influenza due to types A1 and A2.

How To Vaccinate

Initial Vaccination

Shake well. Using aseptic technique, give 1 ml by deep intramuscular injection with a 20 gauge 1-1/2” sterile needle. Administer another 1 ml dose in 3 to 4 weeks at a different injection site using a separate 20 gauge 1-1/2” sterile needle for each injection.


A single 1 ml booster should be administered annually. Additional boosters of encephalomyelitis and/or influenza-containing vaccines manufactured by Schering-Plough may be indicated during epidemics or in areas of endemic exposure. In the event of an outbreak, affected or newly acquired animals should be segregated from the unaffected horses.

EWTF Caution

1. For veterinary use only. Store at 2°-7°C (35°-45°F). Do not freeze.

2. Shake well before use. Use entire contents when first opened. Vaccinate only healthy animals. Do not vaccinate animals during times of stress.

3. Do not vaccinate within 21 days before slaughter.

4. Inject deep into the muscle tissue only. Transient local reactions may occur, especially if product is injected subcutaneously. Occasionally, mild stiffness and soreness may occur two to three days after vaccination in some horses. If allergic response occurs, administer epinephrine.

5. Contains gentamicin and amphotericin B as preservatives.

6. Keep a record of vaccine type, quantity, serial number, expiration date, place of purchase, and date and time of vaccination.

U.S. Veterinary License No. 165A

Schering-Plough Animal Health Corporation, Omaha, Nebraska 68103, U.S.A.

© 1992, 1993, 1994, Schering-Plough Animal Health

All rights reserved.





10 x 1 Dose

10 Single Dose Vials

1 ml Each



Nac No.

556 MORRIS AVE., SUMMIT, NJ, 07901
Telephone:   862-245-4321
Order Desk:   800-648-2118
Fax:   862-245-4935
Customer Service:   800-521-5767
Every effort has been made to ensure the accuracy of the EWTF information published above. However, it remains the responsibility of the readers to familiarize themselves with the product information contained on the US product label or package insert.

Copyright © 2018 North American Compendiums. Updated: 2018-04-26