The Forever Fever refers to an ongoing period of technological progress in the field of Smart Polymer Medicine (SPM) which started in the last decade BFC before gaining prominence in the first and second decades AFC. The term Forever Fever was coined by MetaFox journalist @LivedItLily in her series "Gonzo vs Trillionaire" in 4 AFC, but in Greater Zhōngguó the phenomenon is more commonly known by the term 邪修/xié xiū or cultivating evil (immortality). It has been driven by promising results in the full replacement of parts of multiple organ systems, including basic Neurogenesis, with smart polymers; rather than simply repairing them. It is estimated to have attracted nearly a quadrillion US dollars of investment, due to the expert consensus that it represents a viable path to functional immortality in humans. SPM companies have been criticized as being trillionaire only clubs due to the patents and secrecy put in place by some of the largest investors.

The field of synthetic biology stretches back hundreds of years, however the development of more effective cell dynamic models by Pharmatica Group in the 90s led to the modern era of realistic virtual cell models and the ability to effectively target cancer cells via their surface protein profiles, which has been the single most effective intervention in lengthening human lifespan since everyday access to clean water. The improvement in the quality of synthetic cells did not have a similar breakthrough period, but continued slowly yielding many improvements such as biohybrid brain implants and MemAmps. The 50 year period from the 70s to the 20s saw many practical engineering advances increasing the range of treatments that synthetic biology could be applied to, these included synthetic proteins able to self-assemble into hydrogel networks, synthetic cell systems able to lay down extracellular matrices, scaffolds, synthetic circuits for fine tuning embryo selection eugenics, programmable orthogonal genetic codes, and biocoherence systems such as those pioneered by Nexus.

Up until the last decade BFC the most promising approach to extending longevity appeared to be cell repair via nanobots. The development of microscale devices such as respirocytes, a 1-micron spherical device that can carry hundreds of times more oxygen than a natural red cell, were seen as heralding a new era of medicine. Research on humans was legally prohibited, but many military contractors such as Ný Varangia and Constellis Group paid for the research in the Argentinian Mancomunidad which led to the first surgical implementations of respirocyte fleets in humans, creating soldiers with greatly increased endurance due to better gas-exchange ability. This and other applications of surgical nanotech such as targeted drug delivery, cell destruction, and blood vessel clearing are now in common use. However the inability to create effect sub-microscale devices due to the sticky fingers problem has led to a stagnation in the field of nanotech, with cellular repair techniques for DNA, protein folding, mitochondria, ribosomes, enzymes, and membrane channels remaining out of reach of microscale devices.

Instead, many years of improvements in smart polymers capable of adjusting stiffness, conductivity, and biochemical activity in response to cellular and neural cues started to snowball in the last decade BFC. Smart Polymer Medicine differs from regenerative medicine in its focus on synthetic permanence rather than ongoing cell renewal. Smart polymers self-heal and adapt to metabolic demands, eliminating many risks of scar formation, immune rejection, or uncontrolled cell proliferation. Neural-interface coatings permit communication with the autonomic and central nervous systems, ensuring that polymeric replacements retain the responsiveness of natural organs. This technology began to be commercialised in the first years AFC, firstly with the synthesis of simpler organs such as the bladder and blood vessels, and the first simple organoprinter was installed at Massachusetts General Hospital in 9 AFC. Research is ongoing into techniques for the replacement of more metabolically active organ sections, such as parts of livers, kidneys, and hearts.

The development of artificial myelination, using smart polymers to patch and improve nerve conduction, was another avenue of commercialisation. This was initially funded by Microsynth and Sinogroup who were seeking military applications such as faster signal processing in the brain, however it has seen more use in treating demyelinating diseases and injuries. This led to the development of mesoscale polymeric interfaces able to route signals around damaged neurons, which have shown promise in compensating for neuronal loss in neurodegenerative diseases. Victor Kwan funded startup MindFrame has demonstrated in-situ offloading of hippocampal CA1 processing into connected polymer circuits, leading to speculation that the complete replacement of a human brain might be possible in the near future. Critics point out that the primitive state of brain emulation in copies show that the brain’s astronomical complexity and fragile timing have barely begun to be mapped.