Delaying 12 month vaccinations? How late after the one year birthday can an infant's 12 month vaccinations be delayed?

Why do So? Better late than never. Delaying vaccines have been demonstrated to increase the risk of obtaining the disease while " waiting" in addition, studies have shown that when delayed, the vaccins are often never given at all. Unless there is a specific medical reason to wait, it only has a downside with no upside whatsoever.
Why delay?? Delay means simply loss of protection. Somewhat like driving without insurance. Delay doesn't mean you must start over at some point, it just means the kid remains vulnerable to the diseases they prevent during a period when their body is more vulnerable to the effect of those illnesses. The schedules are based on how early effective protective levels can be provided by the vaccines.