Nobivac® FeLV

Biological name
Feline Leukemia Vaccine, KILLED VIRUS

The only vaccine with proven 2-year duration of immunity for feline leukemia virus (FeLV).1

Features and benefits

A quality core vaccine that protects against feline leukemia
  • The only feline leukemia vaccine labeled to prevent persistent viremia for 2 years after vaccination2
  • 96% of vaccinated cats were protected against persistent viremia after FeLV challenge1
  • In a 2-year study involving 23 FeLV-negative cats:2
    • After 12 weeks, 83% of vaccinates were free of persistent and transient viremia
    • All 11 control cats (100%) developed persistent viremia
    • Results showed that cats developed immunity solely through the initial vaccination series
  • Available in combination with other Nobivac® feline vaccines to provide broader disease protection
  • Optimal choice for healthy outdoor cats


  • Approved for the vaccination of healthy cats as an aid in the prevention of lymphoid tumors caused by, and diseases associated with, feline leukemia virus (FeLV) infection
  • Vaccination with this product prevents persistent viremia in cats exposed to virulent feline leukemia virus
  • Recommended for use in healthy cats 9 weeks of age or older

Safety information

  • 99.99% reaction-free in ongoing surveillance involving millions of doses1
  • Two-year duration of immunity means fewer vaccinations

Please see the product label for further safety information.

Dosage and administration

For cats 9 weeks of age or older:

  • Subcutaneous or intramuscular injection
  • Initial 1-mL dose administered at 9 weeks of age or older
  • Second 1-mL dose administered 3 to 4 weeks later
  • Revaccination every 2 years with a single dose is recommended

For further information, including complete directions and warnings, please see the product label.

Product label(s) and MSDS


  1. Data on file, Merck Animal Health.
  2. Jirjis FF, Davis T, Lane J, et al. Protection against feline leukemia virus challenge for at least 2 years after vaccination with an inactivated feline leukemia virus vaccine. Vet Ther. 2010;11(2):E1–E6.