The herpes zoster vaccine, also known as the shingles vaccine, is generally safe and well tolerated according to a Vaccine Safety Datalink study of 193,083 adults published online in the Journal of Internal Medicine.

More than 1 million people develop shingles every year in the United States. Shingles is a painful contagious rash caused by the dormant chickenpox virus which can reactivate and replicate, damaging the nerve system. The elderly are especially vulnerable because immunity against the virus that causes shingles declines with age.

The VSD project is a collaborative effort between the Centers for Disease Control and Prevention and integrated care organizations, including Kaiser Permanente. The VSD project monitors immunization safety and addresses the gaps in scientific knowledge about any rare and serious events that occur following immunization.

This study examined adverse events after the zoster vaccine was administered to 193,083 adults aged 50 and older from Jan. 1, 2007, to Dec. 31, 2008. Vaccination data were retrieved from electronic health records and collected from eight managed care organizations participating in the VSD project.

Researchers found a small increased risk of local reactions from one to seven days after vaccination. These findings corroborate clinical trials of the vaccine in which there was evidence of a minor local reaction at the injection site in the form of redness and pain.

The study found no increased risk for cerebrovascular diseases; cardiovascular diseases; meningitis, encephalitis, and encephalopathy; Ramsay-Hunt syndrome; or Bell's palsy.

"It's good to know there is no serious adverse reaction to the zoster vaccine. The study supports the CDC's Advisory Committee on Immunization Practices' recommendation and reassures the general public that the vaccine is safe," said study lead author Hung Fu Tseng, PhD, MPH, a research scientist with the Kaiser Permanente Southern California Department of Research & Evaluation in Pasadena, Calif.

The herpes zoster vaccine was licensed in 2006, but few people have been vaccinated, national data shows. The ACIP recommends the vaccine for healthy people age 60 years and older. In 2011, the U.S. Food and Drug Administration approved the use of the herpes zoster vaccine in individuals 50 to 59 years of age. The study results provide important safety data for people in this age group as well as adults 60 and older.