You forgot about individual variation or herd health medicine or maternal antibody variability or compliance or practicality, economics and human fallibility! People mistakenly believe the practice of immunology in human and veterinary medicine is done in favor of the individual
These tend to be places where you can easily access the subcutaneous (fatty areas) under the skin and the needle won't come too close to muscle or bone
or symptoms of thyroid abnormalities such as a neck mass, persistent hoarseness, or difficulty swallowing
Vitamin B12 plays a key role in various bodily functions, including red blood cell production, nerve health, DNA synthesis, and energy metabolism
Refrigeration (2-8C / 36-46F): The Standard Protocol This is the sweet spot
Many people prefer this because they want calm and simple dosing