yes vampire's allergic to silver, zerotime.com and in wickpediya also refere that vapire's allergic to silver,
Silver: When most people think of silver weapons killing monsters they think of silver bullets and werewolves, however, silver stakes, spears and daggers have also been known to slow down and kill vampires. Silver is considered to be a metal of purity and has been used for protection against evil in almost every world culture throughout history. Silver can be melted down to form amulets, jewelry, bullets, daggers and religious symbols such as crucifixes. Silver amulets and daggers can be put into the ground above the grave to prevent evil spirits from escaping. Silver nails drove into coffin lids are said to help prevent evil spirits from rising from the grave.
this para is fom zerotime .com