Experimental serum

The experimental serum is a miscellaneous item in Fallout 4.

Characteristics
A serum unique on a wasteland scale, this container contains a retrovirus capable of returning the super mutant Brian Virgil back to his human form. Although such a cure was theoretically possible before the Great War, reversing the mutation was believed to be an unachievable goal, as the counter-virus would require both a preserved sample of the original DNA and a way to neutralize the FEV. Neither were believed to be possible to achieve, as FEV eliminated the original DNA and no method existed to remove the virus. At least, until Brian Virgil worked on the Institute's FEV project, advancing the understanding of FEV's capabilities beyond pre-War knowledge.The Vault Dweller: "{120}{}{How does the Virus work?}" ZAX 1.2: "{157}{}{My research into the Forced Evolution Virus, or FEV, indicates that it is a shifting-absorptive virus. It copies DNA patterns much like RNA, storing these patterns in exons.}" "{158}{}{These exons, combined with the FEV, are re-injected into the host cells in typical viral infectious fashion. This causes the host cells to 'regenerate' their DNA.}" The Vault Dweller: "{159}{}{How do you catch FEV?}" ZAX 1.2: "{162}{}{FEV is not 'caught', per se. It is not air-transmittable. Typically, infection is through injection, or direct physical contact with an FEV sample.}" The Vault Dweller: "{164}{}{Why isn't FEV affected by radiation?}" ZAX 1.2: ''"{166}{}{The FEV is a megavirus, with a protein sheath reinforced by ionized hydrogen. It is therefore capable of absorbing neutrons without becoming radioactive.}" The Vault Dweller: "{168}{}{If the FEV re-infects the host with its assimilated viral patterns, how does it make a 'better specimen'?}" ZAX 1.2: "{169}{}{The FEV is pre-programmed with introns of corrected DNA appropriate to the proper type of species. It therefore attempts to correct the DNA of the individual.}" "{170}{}{However, as the FEV is partially reliant upon the DNA of the individual, and also includes portions of its own recursive code, the effects can be unpredictable.}" "{171}{}{When inoculated into an individual with significant genetic damage, such as through radiation, it will cause the body's systems to suffer massive overhauling, leading to organ failure and death.}" "{172}{}{In a genetically viable individual, it re-writes portions of DNA, causing accelerated mutation, usually leading to recursive growth due to the FEV's own patterns.}" "{173}{}{This recursive growth leads to an increase in muscle and brain mass, but is often accompanied by disfigurement and damage to existing neural patterns, causing loss of memory.}" The Vault Dweller: "{174}{}{What potential long-term side effects exist?}" ZAX 1.2: "{178}{}{As the FEV causes constant regenerative update to DNA, it would effectively render the subject largely immortal, as cell death would be offset by augmented growth.}" "{179}{}{Additionally, as the gametes of the reproductive system consist of 'half-cells' using split DNA, they could be perceived as 'damage' by FEV, which would 'repair' them, rendering the subject sterile.}" "{180}{}{However, as my laboratory facilities are damaged beyond repair, this is conjectural. I cannot offer physical proof. You will have to, in human terms, 'take my word for it.'}" The Vault Dweller: "{181}{}{Could FEV mutation be corrected with a counter-virus?}" ZAX 1.2: "{184}{}{No. FEV does not retain unaltered original copies of the subject's DNA. Only a virus which re-infected the subject with original DNA could reverse the effects. Additionally, there is no known way to remove the FEV itself.}"'' (ZAX.MSG)

The serum is a retrovirus, using recombinant counter-intron sequences and transcriptive exon strands together with a genetic resequencer to counteract the specific strain of FEV that Virgil was infected with, restoring him to a human state not by reverting to the original DNA, but recreating it using the mutated DNA as basis. The experimental state of the serum and a buggy resequencer do not result in a perfect restoration, leaving portions of the mutated code untouched: Virgil retains some muscle mass after the transformation... And his baldness being apparently cured. However, the cure's effectiveness is limited to the single specific strain Virgil infected himself with and generalizing the formula would take years, if not decades.

Related quests

 * Virgil's Cure: The serum allows Virgil to return to his human form.

Location

 * The Institute, in a container inside the ruined FEV lab.