The vaccination schedule question I get asked weekly, answered plainly

New pet owners ask constantly whether puppy and kitten vaccines are really necessary that early, often after reading conflicting advice online. The plain clinical answer: yes, and the timing is precisely calibrated to a narrow immunity gap that exists whether or not you vaccinate.

Maternal antibodies protect newborns initially but fade on an unpredictable schedule, leaving a gap where a young animal has no protection of its own yet. The multi-dose puppy and kitten schedule exists specifically to catch that gap regardless of when it closes for an individual animal, since vets can't know the exact day it happens.

Skipping doses to "space them out" based on online advice reopens exactly the gap the schedule was designed to close. I still see completely preventable illness from this every year.

Part of the deeper dive: The Practical Pet Owner's Guide: Training, Behavior, and What's Actually Normal.