高齢者に対する帯状疱疹ワクチンと帯状疱疹

【文献名】

Tseng HF, Smith N, Harpaz R, et al. Herpes zoster vaccine in older adults and the risk of subsequent herpes zoster disease. JAMA 2011; 305:160.



【要約】

<Context> 
Approximately 1 million episodes of herpes zoster occur annually in the United States. Although prelicensure data provided evidence that herpes zoster vaccine works in a select study population under idealized circumstances, the vaccine needs to be evaluated in field conditions.



<Objective> 
To evaluate risk of herpes zoster after receipt of herpes zoster vaccine among individuals in general practice settings.



<Design, Setting, and Participants> 
A retrospective cohort study from January 1, 2007, through December 31, 2009, of individuals enrolled in the Kaiser Permanente Southern California health plan. Participants were immunocompetent community-dwelling adults aged 60 years or older. The 75 761 members in the vaccinated cohort were age matched (1:3) to 227 283 unvaccinated members.



<Main Outcome Measure> 
Incidence of herpes zoster.

<Results> 
Herpes zoster vaccine recipients were more likely to be white, women, with more outpatient visits, and fewer chronic diseases. The number of herpes zoster cases among vaccinated individuals was 828 in 130 415 person-years (6.4 per 1000 person-years; 95% confidence interval [CI], 5.9-6.8), and for unvaccinated individuals it was 4606 in 355 659 person-years (13.0 per 1000 person-years; 95% CI, 12.6-13.3). In adjusted analysis, vaccination was associated with a reduced risk of herpes zoster (hazard ratio [HR], 0.45; 95% CI, 0.42-0.48); this reduction occurred in all age strata and among individuals with chronic diseases. Risk of herpes zoster differed by vaccination status to a greater magnitude than the risk of unrelated acute medical conditions, suggesting results for herpes zoster were not due to bias. Ophthalmic herpes zoster (HR, 0.37; 95% CI, 0.23-0.61) and hospitalizations coded as herpes zoster (HR, 0.35; 95% CI, 0.24-0.51) were less likely among vaccine recipients.



<Conclusions> 
Among immunocompetent community-dwelling adults aged 60 years or older, receipt of the herpes zoster vaccine was associated with a lower incidence of herpes zoster. The risk was reduced among all age strata and among individuals with chronic diseases.



【ディスカッション】
 This result shows 55% reduction of Herpes Zoster patients compared with unvaccinated ones and NNP(Number needed to prevent) for 3 years is 71 individuals. But, vaccine price is $161.50 and probably it will be difficult to be paid by public money. Then I want to evaluate cost-effectiveness for this vaccine.
  The over all cost to prevent 1 patient for 3 years is $11466.5. If this effect remains for 10 years, this cost will be lowered to $3,440. And we have to consider the incidence of PHN in Herpes Zoster patients, which is 6.9-18.5% (Mean 12.7%). So The cost to prevent 1 PHN patient for 10 years is $27,085 (\2,085,540). The drug price of post-herpetic neuralgia is \458/day (Pregabalin 300mg/day). So the cost to treat one patient for 10 years is \1,671,700.
  How do you think about this data? Do you want to adopt this vaccine in your clinic and town?

【開催日】
2011年10月19日