What is Herpes Zoster?

Herpes Zoster (also called Zoster or Shingles) is a painful and blistering rash that is caused by the same virus that causes chickenpox. There is no treatment for Zoster so far. After chickenpox sores heal, the virus lies dormant in your nerves and may later reactivate as Zoster or Shingles. In other words, the Zoster virus is already inside you if you have had chickenpox.


Are you at risk?

If you have had chickenpox, the Zoster virus will stay in your nervous system and can re-emerge, though it is hard to tell when exactly it will happen. According to epidemiologic studies, it is generally found that:

  • 95% of adults are at risk for Zoster;
  • 1 in 3 people will get Zoster in their lifetime; and
  • The risk increases substantially after age 50.

Having Zoster does not guarantee immunity from recurrence. People who suffer from immunity deficiency (e.g. diabetes and cancer), high work pressure, sleep deprivation or who are recovering from illness are also belonged to the high-risk group.


How bad a case of Zoster will be?

It is hard to predict how bad a case of Zoster will be. The rash can range from mild to severe, and it can feel as bad as it looks. It can occur in the places where nerves from the spinal cord meet the skin, called the dermatomes. The most common area is along one side of the back and waist, followed by other body parts such as limbs. Most patients describe the pain associated with Zoster as sharp, shooting and throbbing, and that the Zoster can be unusually sensitive to the touch. The Zoster rash can take up to 4 weeks to heal.

The table below summarizes how the Zoster rash will look in different stages:

MildA few blisters appearing on the skin
ModerateA cluster of blisters appearing on the skin
SevereClusters of blisters can merge into a large area resembling a burn


1 in 4 people who get Zoster will experience complication of some kind. One possible complication of Zoster is Post-herpetic Neuralgia (PHN), which is a nerve pain that can last for months or years after the rash is healed. As one gets older, his/her risk for PHN increases.


How does Zoster affect daily life?

Having Zoster may lead to serious physiological and psychological consequence. It will cause pain and discomfort, damage physical appearance and disturb your everyday and social life. Some may suffer from prolonged low-esteem, negativity and anxiety. If the virus attacks eyes or ears, visual or hearing loss will likely be resulted.


How to prevent Zoster?

So far, the most effective way to prevent Zoster is to get vaccinated. Your immune system is usually strong enough to keep the virus in check, but it will weaken as you age, making it easier for Zoster to break through your body’s defenses. As the general painkillers are not enough to ease the pain caused by Zoster and usually come with more side effects, it is therefore important to ask your doctor and get vaccinated as early as possible.



Who is zoster vaccine indicated for?

  • All individuals (men and women) aged 50 or older


Who are not recommended to get vaccinated?

  • People who currently have Zoster
  • People who are allergic to gelatin, neomycin, or any component of the vaccine
  • People who are in primary and acquired immunodeficiency states or on immunosuppressive therapy (including high-dose corticosteroids)
  • People with active untreated tuberculosis


What are the common side effects?

Common side effects associated with zoster vaccine include redness, pain and tenderness, swelling at the site of injection of the vaccine and headache.



  1. People who are under 50 and have had chickenpox are also at risk for zoster. In general, the risk increases with age.
  2. Zoster vaccine is suitable for both men and women
  3. Persons with a reported history of zoster can be vaccinated
  4. Zoster vaccine is not a treatment for Zoster. People who currently have zoster should not get vaccinated.



  1. Centers for Disease Control and Prevention 
  2. US Department of Health and Human Services
  3. US Food and Drug Administration