Do the Benefits of Varicella Vaccination Outweigh the Long‐Term Risks? A Decision‐Analytic Model for Policymakers and Pediatricians

Abstract

Although varicella vaccine is recommended for infants, many physicians and parents have withheld vaccination from infants because of concerns about the vaccine's long-term efficacy. We used a decision-analytic Markov model to examine the effects of decreasing vaccine efficacy on individuals and society. The model incorporated published data on age-specific incidence, morbidity, and mortality rates, as well as data on shifting disease burden from childhood to adulthood as vaccine compliance increases. The effects of 2 vaccination strategies---vaccinating infants at age 12 months and waiting to vaccinate until children are 10 years of age---were compared with the effects of no vaccination. If the efficacy of the vaccine were to decrease by 75%, then 50% compliance with vaccination at age 12 months would save 1800 life-years and 12,800 quality-adjusted life-years annually in the United States. The quality-adjusted life expectancy of individuals vaccinated at age 12 months would be 63 h longer than that of nonvaccinated individuals and would increase to 79 h as vaccination compliance increases and the burden of chickenpox shifts to adulthood. Varicella vaccination of infants at age 12 months appears to be beneficial, even if the efficacy of the vaccine declines substantially.

Sources and Characteristics of Utility Weights for Economic Evaluation of Pediatric Vaccines: A Systematic Review

“…Four modeling studies for varicella met our inclusion criteria. They were performed in The Netherlands [126], the United Kingdom [127], and the United States [128,129], although all used utility weights from a study conducted in the United Kingdom [130], except the study by Rothberg et al [128], which used expert assessments on the Index of Well-Being scale. Again, untested assumptions were applied in some cases, such as the assumption by Van Hoek et al [127] that patients with less than 50 spots would have only 25% of the QALY loss of patients with more than 50 spots.…”

Benefit-Risk Assessment of Vaccines. Part II: Proposal Towards Consolidated Standards of Reporting Quantitative Benefit-Risk Models Applied to Vaccines (BRIVAC)

“…The three strategies involved either (1) vaccinating all infants at 12 months of age, (2) delaying vaccination until 10 years of age and then vaccinating only if a child has no history of varicella or (3) not vaccinating at all. (Example based on Rothberg et al [41]).…”

Varicella vaccination in pediatric kidney and liver transplantation

“…So far, it is unclear whether repeated booster vaccinations are necessary when the probability of being boostered by the wild‐type VZV declines and whether the decrease in wild‐type VZV boosting also affects herpes zoster rates. Only few studies have respected the dynamic and time‐dependent processes of the influence of vaccination on the latent VZV infection, reactivation and reinfection in the general population (81). Thus, the immunological consequences for immunocompromised patients caused by introduction of a general VZV vaccination program in healthy individuals should gain more attention in future studies.…”