There is a growing belief that all feline vaccines must be injected on the tail to prevent cancer. This is not entirely correct, and it is important to clarify this—especially when it comes to Purevax vaccines.
Let’s be very clear:
Purevax vaccines do NOT require tail injection to avoid sarcomas.
Why This Confusion Exists
The recommendation to vaccinate cats on the tail or distal limbs came from concerns about feline injection-site sarcoma (FISS). This cancer was historically associated with older, adjuvanted vaccines, which caused stronger and more persistent local inflammation.
Because sarcomas were difficult to treat when they occurred on the body or between the shoulders, veterinarians shifted injection sites to areas where surgical removal would be easier if a tumor ever developed.
This strategy was site-based risk management, not vaccine-specific.
What Makes Purevax Different
Purevax vaccines are non-adjuvanted. They do not contain aluminum-based adjuvants that are strongly linked to chronic inflammation.
Because of this, Purevax vaccines:
- Cause less local tissue reaction
- Have a much lower association with injection-site sarcoma
- Are considered among the safest injectable feline vaccines available
This means the original reason for mandatory tail vaccination does not apply in the same way to Purevax.
Does This Mean Sarcoma Risk Is Zero?
No vaccine can claim zero risk.
However, with Purevax, the risk is:
- Extremely low
- Comparable to other routine injections
- Not high enough to require tail-only administration
The science supports that vaccine formulation matters more than injection site when it comes to sarcoma risk.
So Where Should Purevax Be Injected?
Purevax can be safely administered:
- On recommended limb sites
- On appropriate lateral body sites
- Following standard feline vaccination protocols
Tail injection may still be used by preference, but it is not required for safety when using Purevax.
Bottom Line
Tail vaccination was developed to manage risks associated with older, adjuvanted vaccines.
Purevax is different.
It is non-adjuvanted, lower in inflammatory response, and does not need to be injected on the tail to avoid sarcomas.
Good vaccination decisions should be based on:
- Vaccine type
- Evidence-based risk
- Proper technique
- Individual patient assessment
Not on outdated fear.
Dr. Geoff Carullo is a Fellow and the current President of the Philippine College of Canine Practitioners.
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