ERT has been shown to lead to better outcomes in MPS II patients. Gene editing therapy
In February 2019, medical scientists working with Sangamo Therapeutics, headquartered in Richmond, California, announced the first  "in body" human gene editing therapy to permanently alter DNA - in a patient with MPS II. Clinical trials by Sangamo involving gene editing using zinc finger nuclease  are ongoing as of February 2019. Prognosis
Earlier onset of symptoms is linked to a worse prognosis. For children who exhibit symptoms between the ages of 2 and 4, death usually occurs by the age of 15 to 20 years. The cause of death is usually due to neurological complications, obstructive airway disease, and cardiac failure. If patients have minimal neurologic involvement, they may survive into their 50s or beyond. Epidemiology
An estimated 2,000 people have MPS II worldwide, 500 of whom live in the United States.A study in the United Kingdom indicated an incidence among males around one in 130,000 male live births. History
The syndrome is named after physician Charles A. Hunter (1873–1955), who first described it in 1917. Research
Beginning in 2010, a phase I/II clinical trial evaluated intrathecal injections of a more concentrated dose of idursulfase than the intravenous formulation used in enzyme replacement therapy infusions, in hopes of preventing the cognitive decline associated with the severe form of the condition. Results were reported in October 2013.
: 543–45  English vaccine was occasionally made in sheep during World War I but from 1946 only sheep were used.In the late 1940s and early 1950s, Leslie Collier, an English microbiologist working at the Lister Institute of Preventive Medicine, developed a method for producing a heat-stable freeze-dried vaccine in powdered form. Collier added 0.5% phenol to the vaccine to reduce the number of bacterial contaminants but the key stage was to add 5% peptone to the liquid vaccine before it was dispensed into ampoules. This protected the virus during the freeze drying process. After drying the ampoules were sealed under nitrogen. Like other vaccines, once reconstituted it became ineffective after 1–2 days at ambient temperatures. However, the dried vaccine was 100% effective when reconstituted after 6 months storage at 37 °C (99 °F) allowing it to be transported to, and stored in, remote tropical areas. Colliers method was increasingly used and, with minor modifications, became the standard for vaccine production adopted by the WHO Smallpox Eradication Unit when it initiated its global smallpox eradication campaign in 1967, at which time 23 of 59 manufacturers were using the Lister strain.