"U.S. regulators have approved a new more effective vaccine to prevent painful shingles https which is caused by the chickenpox virus https Drugmaker GlaxoSmithKline said the Food and Drug Administration approved it late Friday. It will be the second shingles vaccine in the U.S. market. Merck launched the first one in . Studies paid for by Glaxo found it prevents shingles in about  percent of people. Mercks is about  percent effective. Both versions are for adults  and older. The U.S. Centers for Disease Control and Prevention though recommends vaccination for those  or older partly because it loses effectiveness over time. Anyone whos had chickenpox  nearly everyone over   harbors the varicellazoster virus that causes the disease. The virus can resurface decades later triggering painful sores on one side of the body. About  to  percent of those who get shingles also develop debilitating nerve pain that can last for months even years. About onethird of people who have had chickenpox get shingles. Thats about  million Americans a year. But once someone has recovered from shingles it rarely reoccurs. Chickenpox was a very common childhood illness until a Merck vaccine was introduced two decades ago its now part of routine childhood shots https GlaxoSmithKline PLC said the price of its shingles vaccine called Shingrix will be  for the required two shots. Merck  Co.s oneshot Zostavax costs . Most insurance plans cover it. The two vaccines are made differently. Glaxos is genetically engineered and includes an ingredient that boosts effectiveness. In addition to preventing shingles it also reduces the risk of nerve pain by nearly  percent. Glaxo studies also show it retains about  percent of its effectiveness for four years and followup studies indicate it lasts years longer according to Dr. Leonard Friedland Glaxos vaccines director for North America. Mercks vaccine uses a live but weakened virus so it cant be used by people with compromised immune systems. It reduces risk of shingles by half and risk of nerve pain by  percent according to the CDC. One study found it doesnt prevent shingles after eight years. More research is being done. Glaxo is testing its vaccine against Mercks. Meanwhile Merck has been testing a different vaccine on cancer patients and people with compromised immune systems."