Varicella and herpes zoster vaccine development: lessons learned

ABSTRACT

Introduction: Before vaccination, varicella zoster virus (VZV), which is endemic worldwide, led to almost universal infection. This neurotropic virus persists lifelong by establishing latency in sensory ganglia, where its reactivation is controlled by VZV-specific T-cell immunity. Lifetime risk of VZV reactivation (zoster) is around 30%. Vaccine development was galvanised by the economic and societal burden of VZV, including debilitating zoster complications that largely affect older individuals.

Areas covered: We describe the story of development, licensing and implementation of live attenuated vaccines against varicella and zoster. We consider the complex backdrop of VZV virology, pathogenesis and immune responses in the absence of suitable animal models and examine the changing epidemiology of VZV disease. We review the vaccines’ efficacy, safety, effectiveness and coverage using evidence from trials, observational studies from large routine health datasets and clinical post-marketing surveillance studies and outline newer developments in subunit and inactivated vaccines.

Expert commentary: Safe and effective, varicella and zoster vaccines have already made major inroads into reducing the burden of VZV disease globally. As these live vaccines have the potential to reactivate and cause clinical disease, developing alternatives that do not establish latency is an attractive prospect but will require better understanding of latency mechanisms.

KEYWORDS:

• Varicella
• herpes zoster
• live attenuated vaccine
• subunit vaccine
• vaccine safety
• vaccine efficacy
• vaccine effectiveness
• post-marketing surveillance

Declaration of interest

C Warren-Gash is supported by a Wellcome Intermediate Clinical Fellowship (201440_Z_16_Z). J.Breuer receives funding from the UCL/UCLH NIHR Biomedical Resource Centre. None of the authors have any other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Additional information

Funding

The manuscript was not funded.