an infant is converted into a vampire( a great idea for a movie ).So would he/she still develop fangs if his/her teeth havent grown out yet before conversion. And what are the chances of that baby vampire to survive.
justify your answer .
Re: a silly but serious question
Vampire depends on the type… the classic Slavic Wampyr is an undead creature so the Child would have had to be dead to be turned?
The Pyshcotic Sanguinarian Vampire or Modern Cinema is created when bitten by a Master Vampire… so yes the Child would I assume develop fangs very soon. 
If the Vampire type is like the Mythic Vetalla of India then it never started as a human in first place, same with Persian and Arab as well as Hebrew Mythology.
In the New World the baby might turn into a bat and start flying about… in which case get the net ready.
… Like I said depends on the Vampire… theres more than one type.