HERPES ZOSTER ( SHINGLES ) And Herpes Zoster Vaccines
Stanley A . Gall , MD
Herpes Zoster ( HZ ) is thought of as a localized cutaneous skin eruption within a unilateral dermatome resulting from reactivation of latent Herpes Zoster virus ( chicken pox virus ). While approximately 95 percent of American adults have latent HZ virus from a primary chicken pox infection , 20 percent will develop HZ . ( 1 ) The incidence increases with age from five cases per 1,000 adults aged 50-59 years to 11 cases per 1,000 adults aged 80 years . While this unilateral dermatomal rash consists of multiple vesicles and pain , it usually resolves within one to two weeks . However , HZ may produce additional complications such as neuralgia , ocular pathologies , myelitis and encephalitis . Approximately 10-20 percent of patients with HZ will develop post herpetic neuralgia or ophthalmicus . ( PHOTO # 1 ) ( 2 ). Multiple studies have reported the occurrence of stroke after shingles and a recent report shows the odds of a cerebrovascular event were significantly increased up to one year after HZ onset ( ORS = P = 1.22 ; 95 percent , Cl 1.15-1.29 )( 3 ). HZ has been associated as a significant risk factor for giant cell arteritis . ( 4 )
Zoster Vaccine live ( ZVL ) ( ZOSTAVAX ) has been marketed by Merck and Company as a 1-dose line attenuated strain of Varicella Zoster Virus ( VZV ) for the prevention of Herpes Zoster disease in immunocompetent adults aged 50 years of age , and recommended by the advisory committee on Immunizations Practice ( ACIP ) for immunocompetent adults aged 60 years . ( 5 ) Since licensure , vaccine usage has increased yearly and by 2016 , 33 percent of adults 60 years reported receiving the vaccine . The overall incidence of HZ per 1,000 person years was significantly reduced by ZVL vaccine from 11.12 / 1000 person years in the placebo group to 5.42 / 1000 person years in the vaccine group ( P = < 0.001 ) ( table 1 ).
The incidence of HZ was reduced by 51.3 percent . 1 ( P = < 0.001 ) and the vaccine efficacy among subjects 70 years was 55.4 percent . Six subsequent studies have shown that ZVL effectiveness against Herpes Zoster would decline to zero 4-12 years following vaccination depending on age at vaccination . ( 7 & 8 ) ( See Photo # 2 ).
SHINGRIX , the Zoster vaccine recombinant { RZV ), a 2-dose subunit vaccine , was approved by the Food and Drug Administrations ( FDA ) on October 20 , 2017 and recommended by the ACIP on October 25 , 2017 . The efficacy for the prevention of HZ was 96.9 percent { 95 percent Cl = 89.6-99.3 in persons aged 50-59 and 97.4 percent ( 95 percent Cl = 90.1-99.7 ) in persons 60-69 years . The vaccine efficacy in persons 70 year was 91.3 percent ( 95 percent Cl = 86.8-94.5 ). The vaccine efficacy remained at these levels for the four years of the study . ( 9 & 10 ) ( Table 2 )
The following recommendations were approved by ACIP in October 2017 after reviewing the above data comparing RZV vaccine ( Shingrix ) and ZVL vaccine ( ZOSTAVAX ). ( 11 )
1 . RZV is recommended for immunocompetent adults aged 50 years .
2 . RZV is recommended for immunocompetent adults previously vaccinated with ZVL .
3 . RZV is preferred over ZVL .
Vaccinating adults age 50 years will prevent disease in midlife and will provide protection for years greater than four years . Since ZVL recipients ’ protection wanes with time and RZV recipients ’ reactogenicity and immunological profiles were similar regardless of prior ZVL , therefore , ZVL recipients will benefit from vaccination with RZV .
RZV may be used in adults aged 50 years irrespective of prior receipt of either varicella vaccine or ZVL , and does not require screening for a history of chicken pox . The second dose of RZV should be given two to six months after the first dose . RZV is administered intramuscularly . The vaccine series does not need to be restarted if the second dose is given greater than six months after the first dose . Two doses are necessary regardless of prior history of Herpes Zoster or prior receipt of ZVL .
The timing of RZV for persons previously vaccinated with ZVL will be an issue . Safety and immunogenicity studies done with patients five years after ZVL show no concerns and although no data or theoretical concerns would indicate RZV would be less safe or effective if administered at an interval greater than five years . Expert opinion suggests RZV should not be given sooner than two months of receipt of ZVL .
Special situations :
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