A fresh look at varicella vaccination

Area of Science:

• Virology and Immunology
• Vaccine Development and Efficacy
• Public Health and Epidemiology

Background:

• The varicella zoster virus (VZV) causes chickenpox and can reactivate as zoster (shingles).
• Live attenuated varicella vaccine, developed by Michiaki Takahashi in 1974, has been crucial in controlling VZV.
• The fluorescent antibody to VZV membrane antigen test (FAMA) enabled the assessment of vaccine efficacy.

Purpose of the Study:

• To review the efficacy and safety of the varicella vaccine.
• To discuss the impact of universal varicella vaccination on varicella and zoster incidence.
• To highlight the potential of VZV gE subunit vaccines for zoster prevention.

Main Methods:

• Review of historical development and clinical application of the varicella vaccine.
• Analysis of epidemiological data on varicella and zoster prevalence post-vaccination.
• Evaluation of vaccine virus reactivation rates compared to wild-type VZV.
• Assessment of the safety and efficacy of adjuvanted subunit vaccines targeting VZV gE.

Main Results:

• Universal varicella vaccination has significantly reduced chickenpox incidence.
• The vaccine has indirectly prevented a predicted zoster epidemic by limiting wild-type VZV circulation.
• The varicella vaccine virus shows lower reactivation rates than wild-type VZV.
• An adjuvanted subunit vaccine targeting VZV gE demonstrates safety and efficacy in preventing zoster.

Conclusions:

• The varicella vaccine is highly effective and safe, leading to near elimination of chickenpox.
• Vaccine-induced reduction in VZV circulation has unexpectedly mitigated zoster outbreaks.
• VZV reactivation, beyond rash and neuralgia, can cause serious neurological and vascular conditions, underscoring the importance of prevention.