The effect of higher levels of maternally derived antibodies on the response to vaccination is not known. However, on the basis of field use, it is expected that in the majority of cats, the levels of maternally derived antibodies that will be present at 9 weeks of age will not interfere with the response to vaccination. Vaccination has no known beneficial effect in cats already infected with FeLV. Therefore, diagnostic testing of cats for the presence of feline leukaemia (FeLV) core protein p27 in serum prior to vaccination may be advisable.

The live vaccine strains may spread to unvaccinated animals, but do not cause diseases.

Disposal: Any unused vaccine or waste material should be disposed of in accordance with local requirements.