They include a live attenuated virus vaccine, Zostavax, and an adjuvanted subunit vaccine, Shingrix.A review by Cochrane concluded that Zostavax was useful for preventing shingles for at least three years. This equates to about 50% relative risk reduction. The vaccine reduced rates of persistent, severe pain after shingles by 66% in people who contracted shingles despite vaccination. Vaccine efficacy was maintained through four years of follow up. It has been recommended that people with primary or acquired immunodeficiency should not receive the live vaccine.Two doses of Shingrix are recommended, which provide about 90% protection at 3.5 years. As of 2016, it had been studied only in people with an intact immune system. It appears to also be effective in the very old.In the UK, shingles vaccination is offered by the National Health Service (NHS) to all people in their 70s. As of 2021 Zostavax is the usual vaccine, but Shingrix vaccine is recommended if Zostavax is unsuitable, for example for those with immune system issues. Vaccination is not available to people over 80 as "it seems to be less effective in this age group". By August 2017, just under half of eligible 70–78 year olds had been vaccinated. About 3% of those eligible by age have conditions that suppress their immune system, and should not receive Zostavax. There had been 1,104 adverse reaction reports by April 2018. In the US, it is recommended that healthy adults 50 years and older receive two doses of Shingrix, two to six months apart.
According to a study in North Carolina, "black subjects were significantly less likely to develop zoster than were white subjects." It is unclear whether the risk is different by sex. Other potential risk factors include mechanical trauma and exposure to immunotoxins.There is no strong evidence for a genetic link or a link to family history. A 2008 study showed that people with close relatives who had shingles were twice as likely to develop it themselves, but a 2010 study found no such link.Adults with latent VZV infection who are exposed intermittently to children with chickenpox receive an immune boost. This periodic boost to the immune system helps to prevent shingles in older adults. When routine chickenpox vaccination was introduced in the United States, there was concern that, because older adults would no longer receive this natural periodic boost, there would be an increase in the incidence of shingles. Multiple studies and surveillance data, at least when viewed superficially, demonstrate no consistent trends in incidence in the U.S. since the chickenpox vaccination program began in 1995. However, upon closer inspection, the two studies that showed no increase in shingles incidence were conducted among populations where varicella vaccination was not as yet widespread in the community. A later study by Patel et al. concluded that since the introduction of the chickenpox vaccine, hospitalization costs for complications of shingles increased by more than $700 million annually for those over age 60. Another study by Yih et al.