Immortality

Immortality is the ability to have an infinite lifespan. It is worth noting that "immortality" in the world of The Vampire Diaries and The Originals, is not immunity to death; Elijah stated that every creature must have a weakness and that nature would never allow a truly immortal being to exist, this was thought proven false as Silas and Amara were seen as truly immortal, however, their immortality was stripped from them by The Cure.

Professor Atticus Shane said that human blood was the life force of an immortal.

Original Vampires

The Original Vampires are immune to natural death, physical aging, diseases, and illnesses.
An Original can be weakened by werewolf venom, which will eventually cause them to hallucinate, along with become crazy and suspicious of everything. Though unlike normal Vampires the effects are only temporary and they will recover within a day. Vervain can also be used to weaken and slow them down, though less so than a normal vampire.
Though they can't be killed permanently by regular wooden stakes and weapons, a wooden stake through the heart will neutralize an Original Vampire, appearing as if they were dead, but they will revive within a few hours.
If an Original Vampire is stabbed through the heart with one of the White Oak Ash Daggers, silver daggers dipped in the ash of the White Oak Tree, it will kill an Original vampire, but only as long as the dagger remains in their heart. The daggers must be dipped in the ash before each use or it will lose its effect, even if it was removed for less than a minute.
They can also be affected by cursed objects, though not being able to kill them, they can suffer great damage or be nuetrilized.
The only way to permanently kill an Original Vampire is to stab them in the heart with a stake made from the White Oak Tree, though will be destroyed with the Original unless made not to, with great enough magic, as magic is stated to be able to kill all things, if enough of it can be conjured, or, though not specifically proven, by removing their heart, or head pressumably, after being weakened to the brink of death by magic.

Vampires

Vampires are immune to natural death, physical aging, diseases, and most illnesses.

Silas' tomb.
The only illness that can weaken or kill a vampire is werewolf venom, which will infect the wound and spread through the bloodstream. After that the vampire will start to hallucinate and cough up blood. Ultimately the vampire dies, crazy and suspicious of everything.
Vervain can also be used to weaken and slow down a vampire. Though in come cases Vampires have shown to grow at least somewhat of an immunity to its effects through taking doses
Wooden bullets are usually used to weaken vampires, and kill normal vampires if made right.
The only way to kill a vampire is to rip out their heart, burn or decapitate them, and the most well known method, a wooden stake through the heart. Magic can also be used to kill a vampire, as magic is stated to be able to kill all things, if enough of it can be conjured.
Normal vampires will also die in the event that the Original Vampire who's bloodline they are apart of dies, though it usually takes within a few hours to happen.

Werewolves

It is unknown whether or not werewolves fit into this category. Because they are living creatures, it is unclear if they are resistant to the process or continue to age naturally. If a werewolf becomes a hybrid, he/she will not age. It is possible that their healing factor slows down their aging.

Original Hybrid

The Original Hybrid, Niklaus Mikaelson , is immune to natural death, physical aging, diseases, most illnesses, sunlight, and werewolf venom, along with being able to heal from any damage from something made of silver.
Because of his werewolf heritage Klaus is also affected by wolfsbane, but he cannot be nuetralized by the White Oak Ash Daggers, nor by regular wooden weapons, albiet they still cause great pain.
The only way to permanently kill Klaus is to stab him in the heart with a stake made from the White Oak Tree, though will be destroyed along with him unless made not to, with great enough magic, as magic is stated to be able to kill all things, if enough of it can be conjured, or, though not specifically proven, by removing his heart, or head pressumably, after being weakened to the brink of death by magic.

Hybrids

Hybrids are Immortal because they are simply Werewolves turned into Vampires.
The only way to kill a hybrid is through decapitation or heart extraction.

Witches

Witches can use spells and herbs to delay the aging process, but it will eventually catch up with them.
Unless they are killed and have their body preserved, in which when they are awakened they'll look the same as they did when they died.
Silas was said to be the world's first immortal/Vampire. He was originally a witch who helped create a spell that would grant him immortality. However, he was later buried alive.

Spell

The Immortality Spell is a spell casted and created by Silas and Qetsiyah and adopted by Esther. The spell was used to immortalise Silas and the Original Family.

Uses and Witches:

Qetsiyah was the first witch to use and create the spell to immortalise Silas and Amara. The spell is incredibly powerful and is forbidden by the Natural Elements.

Esther was the second and last witch to cast the spell in the series. She called on the White Oak Tree for immortality and the sun for life and used the spell to make her children into powerful immortals.

Immortals

The first immortal being who are unconditionally and truly immortal, being unable to die unless cured of their immortality.

Gallery

Trivia

Blood is the life-force of an Immortal.
The White Oak Tree is one of Nature's sources of immortality.
Unlike The Original Vampires, Silas is truly immortal. This is because he used a different version of The Immortality Spell.
There are two known ways to cure immortality: A spell and a potion.