A zoster vaccine is a vaccine that reduces the incidence of herpes zoster (shingles), a disease caused by reactivation of the varicella zoster virus, which is also responsible for chickenpox. Shingles provokes a painful rash with blisters, and can be followed by chronic pain (postherpetic neuralgia), as well as other complications. Older people are more often affected, as are people with weakened immune systems (immunosuppression). Both shingles and postherpetic neuralgia can be prevented by vaccination.Two zoster vaccines have been approved for use in people over 50 years old. Shingrix (GSK) is a recombinant subunit vaccine which has been used in many countries since 2017. Zostavax (Merck), in use since 2006, is an attenuated vaccine which consists of a larger-than-normal dose of chickenpox vaccine. Unlike Shingrix, Zostavax is not suitable for people with immunosuppression or diseases that affect the immune system. Zostavax was discontinued in the United States in November 2020.Shingrix appears to prevent more cases of shingles than Zostavax, although side effects seem to be more frequent.Another vaccine, known as varicella vaccine, is used to prevent diseases caused by the same virus. Medical uses
Zoster vaccination is used to prevent shingles and its complications, including postherpetic neuralgia. It can be considered a therapeutic vaccine, given that it is used to treat a latent virus that has remained dormant in cells since chicken pox infection earlier in life. The two available zoster vaccines are intended for use in people over the age of 50.
Intermittent claudication, also known as vascular claudication, is a symptom that describes muscle pain on mild exertion (ache, cramp, numbness or sense of fatigue), classically in the calf muscle, which occurs during exercise, such as walking, and is relieved by a short period of rest. It is classically associated with early-stage peripheral artery disease, and can progress to critical limb ischemia unless treated or risk factors are modified and maintained. Claudication derives from the Latin verb claudicare, "to limp". Signs and symptoms
One of the hallmarks of arterial claudication is that it occurs intermittently. It disappears after a very brief rest and the patient can start walking again until the pain recurs. The following signs are general signs of atherosclerosis of the lower extremity arteries:
cyanosis
atrophic changes like loss of hair, shiny skin
decreased temperature
decreased pulse
redness when limb is returned to a "dependent" position (part of Buergers test)The six "P"s of ischemia
Pain
Pallor (increased)
Pulse (decreased)
Perishing cold
Paraesthesia
Paralysis

Causes
Most commonly, intermittent (or vascular or arterial) claudication is due to peripheral arterial disease which implies significant atherosclerotic blockages resulting in arterial insufficiency. Other uncommon causes are coarctation of the aorta, Trousseau disease and Beurgers disease (Thromboangiitis obliterans), in which vasculitis occurs. Raynauds phenomenon functional vasospasm. It is distinct from neurogenic claudication, which is associated with lumbar spinal stenosis. It is strongly associated with smoking, hypertension, and diabetes. Diagnosis
Intermittent claudication is a symptom and is by definition diagnosed by a patient reporting a history of leg pain with walking relieved by rest.