The U.S. Centers for Disease Control and Prevention recommended on Thursday that people aged 60 and older get Merck & Co. Inc’s vaccine Zostavax to protect them against shingles.

Shingles, also known as herpes zoster, is a skin rash caused by the same virus that causes chickenpox, namely the Varicella zoster virus (VZV). After an individual has chickenpox, this virus lives in the nervous system and is never fully cleared from the body. Under certain circumstances, such as emotional stress, immune deficiency or cancer, the virus reactivates causing shingles.

Anyone who has ever had chickenpox is at risk for shingles, although it occurs most commonly in people over the age of 60.

It has been estimated that up to 1,000,000 cases of shingles occur each year in the U.S. and half of those occur in people 60 and older. More than 43 million adults over the age of 60 in the U.S. are estimated to be at risk for shingles.

The CDC said the recommendation replaces a provisional one made in 2006 after the U.S. Food and Drug Administration approved the vaccine, which had sales of $236 million in 2007.

Zostavax was found to cut the occurrence of shingles by 50 percent in people age 60 and older. The CDC said that for people ages 60 to 69, it cuts the occurrence of the disease by 64 percent.

Dr. Jane Seward, deputy director of the CDC’s division of viral diseases said the “vaccine provides an exciting new tool for preventing shingles and its serious complications,” Reuters reports.

The most common side effects of the vaccine are redness, pain, tenderness, itching and swelling at the injection site, as well as headache, the CDC said.

The CDC recommendation was made public in the May 15 online edition of its Mortality and Morbidity Weekly Report.