By IDSE News Staff
A new study found that zoster vaccine live (Zostavax, Merck) may prevent stroke in some older adults, according to preliminary research presented at the 2020 American Stroke Association’s International Stroke Conference, in Los Angeles (poster TP493).
To help determine whether the shingles vaccine reduces the risk for stroke, the researchers reviewed the Medicare health records of more than 1 million Medicare fee-for-service beneficiaries aged 66 years or older who had no history of stroke and who were vaccinated with zoster vaccine live between 2008 and 2014, and followed them for an average of almost four years. That group was matched with the same number of Medicare fee-for-service beneficiaries who did not receive the shingles vaccine with the same four-year follow-up. To examine the effect of the vaccine on risk for stroke, researchers controlled for age, sex, race, medications and coexisting health conditions.
Researchers found the following:
- Receiving the shingles vaccine lowered the risk for stroke by about 16%, lowered the risk for ischemic stroke by about 18%, and lowered the risk for hemorrhagic stroke by about 12%.
- The vaccine’s protection was strongest among people aged 66 to 79 years.
- Among those under the age of 80 years, the shingles vaccine reduced the risk for stroke by nearly 20%; and in those older than 80, reduced the risk by about 10%.
“The reason for increased risk of stroke after a shingles infection may be due to inflammation caused by the virus,” said Quanhe Yang, PhD, the lead study author and a senior scientist at the CDC.
More than 99% of people aged 40 years or older in the United States carry dormant varicella-zoster virus. Shingles is a reactivation of the chickenpox virus and typically occurs after age 50. The risk for developing shingles increases with age and other health conditions.
“One in three people who have had chickenpox develop shingles in their lifetime,” Dr. Yang said.
“The Zoster Vaccine Live helps to prevent shingles and reduces the risk for shingles by about 51%. But its effect declines with increased age, about 64% in people 60-69 years, about 41% for ages 70-79 years and about 18% in those 80 years or older.”
This study was conducted when the only shingles vaccine was zoster vaccine live (available since 2006). The newest shingles vaccine, adjuvanted, non-live recombinant shingles vaccine (Shingrix, GlaxoSmithKline) (available since 2017), is now the preferred vaccine recommended by the CDC’s Advisory Committee on Immunization Practices. Future studies are needed to confirm the link between zoster vaccine live and stroke and to determine any association between adjuvanted, non-live recombinant shingles vaccine and the risk for stroke.
