Vaccination recommendations will vary by country, product, age of pet, prior vaccination history, lifestyle, and other factors. It may also even vary by vet, as the guidelines have changed somewhat in recent years.
Your vet is best able to tell you what protocol is most suitable for your pet.
In general, my protocol for the FVRCP vaccine is:
- Kittens under 16 weeks: vaccinate at 8, 12, and 16 weeks.
- Cats over 16 weeks but incomplete or unknown kitten series: initial dose followed by booster in 3-4 weeks.
- Vaccinate at 1 year following initial series.
- Vaccinate every 3 years thereafter
If kept current, there should be no need to repeat the multiple vaccine booster series each year; a single booster dose will suffice.
In the recent guidelines from the American Association of Feline Practitioners, some vets have started recommending an FVRCP booster 6 months after the initial series, rather than 1 year, as it may confer better immunity for some kittens. Practically, I find this challenging for many cat owners to comply with as it will requires an extra vet visit. This type of protocol may be off-label for some products.
More detailed reading on the vaccination guidelines: