What are varicella and herpes zoster?

Varicella (chickenpox) and herpes zoster (shingles) are both caused by the same virus — varicella-zoster virus (VZV), an alpha-herpesvirus. Primary VZV infection causes varicella — a highly contagious childhood illness with widespread vesicular rash, fever and malaise. The virus then hides in dorsal root ganglia and cranial nerve ganglia for life. When immunity declines (usually with ageing or immunosuppression), the latent virus can reactivate to cause herpes zoster — a painful, dermatomal vesicular rash.

What is postherpetic neuralgia and why is it so feared?

Postherpetic neuralgia (PHN) is the most common serious complication of herpes zoster — pain persisting more than 90 days after the rash heals, from nerve damage caused by VZV inflammation. The pain is severe and profoundly debilitating — described as burning, electric shock-like, stabbing, or as exquisite sensitivity to light touch (allodynia — even the touch of clothing on affected skin causes intense pain). Approximately 30% of people over 60 who get shingles develop PHN; risk increases further with age. Quality of life impact is immense — PHN causes depression, sleep disruption, inability to work and social isolation. The Shingrix vaccine prevents PHN in >90% of cases — the most compelling reason for zoster vaccination.

What is Shingrix and why is it recommended?

Shingrix (recombinant zoster vaccine, GSK) is a two-dose intramuscular vaccine containing VZV glycoprotein E plus a powerful AS01B adjuvant. FDA-approved in 2017, it achieves over 90% efficacy against shingles across all age groups — dramatically superior to the older live vaccine (Zostavax, approximately 51% overall efficacy declining sharply with age). Shingrix is recommended for: all adults ≥50 years (regardless of prior varicella/chickenpox history or prior Zostavax vaccination); immunocompromised adults ≥19 years. Two doses are given 2-6 months apart (or 1-2 months apart if immunocompromised). Key advantage over older vaccine: does not contain live virus, so can be given to immunocompromised patients.

Who is at highest risk from varicella?

Varicella is more severe and potentially lethal in: adults (varicella pneumonia risk — 1 in 400 adult cases; higher in smokers, immunocompromised, late pregnancy); pregnant women (varicella pneumonia 10-40% mortality without treatment; congenital varicella syndrome if infection in first 20 weeks; neonatal varicella risk if mother develops rash within 5 days of delivery); immunocompromised patients (disseminated varicella — haemorrhagic, multi-organ involvement, very high mortality); and premature neonates.

How is varicella/shingles treated?

Varicella in children: usually supportive (antihistamines for itch; paracetamol for fever — NOT aspirin); antiviral (aciclovir) indicated for high-risk children (immunocompromised, chronic skin/lung disease, older children/adolescents) started within 24 hours of rash. Varicella in adults and immunocompromised: IV or oral aciclovir (or valaciclovir). Herpes zoster: antiviral (valaciclovir 1g TDS or famciclovir 250mg TDS × 7 days — started within 72 hours of rash for maximum benefit); analgesia; PHN: gabapentin, pregabalin, tricyclic antidepressants, topical agents.

How does GMJ News cover VZV?

GMJ News covers WHO varicella and zoster data, Shingrix efficacy and recommendations, PHN burden and management, zoster ophthalmicus, varicella in pregnancy, and VZIG post-exposure prophylaxis. Varicella vaccination is increasingly important in Georgia's immunisation programme, and herpes zoster/PHN are common in Georgia's ageing population — directly relevant to PHIG's immunisation and ageing health programmes.

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Varicella and Herpes Zoster

GMJ News knowledge hub · last reviewed September 2026 · Georgian Medical Journal

Summary Statistics Glossary GMJ news FAQ Documents Organizations Research

Varicella-zoster virus (VZV) causes two distinct clinical diseases: varicella (chickenpox — primary infection, affecting approximately 90 million children annually) and herpes zoster (shingles — reactivation of latent VZV decades after primary infection, affecting approximately 1 in 3 people during their lifetime), with postherpetic neuralgia (PHN) — severe persistent pain lasting months to years after rash healing — representing the most debilitating complication (WHO). Shingrix (recombinant zoster vaccine — RZV) — approved by FDA in 2017 and recommended for adults aged ≥50 — achieves over 90% effectiveness against shingles and over 90% against PHN, representing the most effective vaccine against reactivation of a latent virus ever developed.

Key messages

1 in 3 people develop shingles — Shingrix >90% effective

1 in 3 people develop herpes zoster (shingles) during their lifetime. Shingrix (recombinant zoster vaccine) achieves over 90% efficacy against shingles and postherpetic neuralgia — one of the most effective vaccines ever developed for an adult condition (WHO).

Same virus — two diseases

Varicella-zoster virus (VZV) causes two clinically distinct diseases: varicella (chickenpox — primary infection) in childhood; and herpes zoster (shingles — reactivation of latent VZV in dorsal root ganglia) in adults, typically after age 50 when cell-mediated immunity wanes.

Postherpetic neuralgia — debilitating pain

Postherpetic neuralgia (PHN) — severe burning, shooting or electric pain persisting months to years after the zoster rash — is the most feared complication, affecting approximately 30% of shingles patients over 60 and causing profound disability and depression.

Antivirals reduce severity if started early

Aciclovir, valaciclovir or famciclovir — started within 72 hours of rash onset — reduce shingles duration, severity, and risk of PHN. Late initiation (>72 hours after rash) provides diminishing benefit.

High-risk groups: varicella in adults, immunocompromised, pregnancy

Varicella is more severe in adults (pneumonia risk), pregnant women (varicella pneumonia 10-40% mortality; neonatal varicella if exposure within 5 days of delivery), and immunocompromised patients (disseminated disease). VZIG post-exposure prophylaxis prevents or attenuates disease in high-risk seronegative contacts.

VZV can cause stroke in elderly

Post-zoster vasculopathy — cerebrovascular disease from VZV-induced arterial inflammation — increases stroke risk after shingles, particularly zoster ophthalmicus. This risk is reduced by antiviral treatment.

Key statistics

~90M

varicella cases/year globally (predominantly children)

WHO

1 in 3

people develop herpes zoster in their lifetime

WHO

>90%

Shingrix (RZV) efficacy against herpes zoster

NEJM/FDA

~30%

of shingles patients over 60 develop PHN

WHO

<72hr

antiviral treatment window for maximum shingles benefit

WHO

2017

year Shingrix FDA-approved — >90% efficacy across age groups

FDA

Herpes zoster incidence by age group (per 1,000 person-years) — WHO/epidemiological data

Source: WHO. Risk increases dramatically with age; immunocompromised patients at highest risk at any age.

Glossary of key terms

VZV (Varicella-zoster virus)
WHOA highly contagious alpha-herpesvirus — transmitted by respiratory droplets and direct contact with vesicle fluid. Primary infection causes varicella (chickenpox); the virus then establishes latency in dorsal root and cranial nerve ganglia, where it can reactivate decades later to cause herpes zoster.

Herpes zoster (shingles)
WHOReactivation of latent VZV from dorsal root ganglia — causing painful unilateral dermatomal vesicular rash. Typically affects one or two adjacent dermatomes on trunk, head/neck. Prodrome of pain/tingling precedes rash by 2-3 days. Most cases resolve in 2-4 weeks; PHN can persist for months or years.

Postherpetic neuralgia (PHN)
WHO/NeurologyPain persisting more than 90 days after zoster rash onset — caused by nerve fibre damage from VZV-induced inflammation. Severe burning, electric shock or allodynic pain (pain from light touch). Management: tricyclic antidepressants (amitriptyline); gabapentin/pregabalin; topical lidocaine/capsaicin patches; opioids for refractory cases.

Shingrix (recombinant zoster vaccine — RZV)
GSK/FDA 2017A 2-dose adjuvanted subunit vaccine — containing VZV glycoprotein E + AS01B adjuvant. Efficacy: >96% against herpes zoster in adults 50-69 years; >91% in those ≥70; and >90% against PHN. Dramatically superior to the previous live zoster vaccine (Zostavax — approximately 51% efficacy declining with age). The gold standard adult shingles vaccine. Two IM doses 2-6 months apart. Can be given to immunocompromised patients (inactivated vaccine).

Zoster ophthalmicus
WHO/OphthalmologyVZV reactivation in the ophthalmic branch of the trigeminal nerve (V1) — causing periorbital zoster rash, conjunctivitis, uveitis, keratitis and — potentially — acute retinal necrosis or stroke (VZV vasculopathy). Hutchinson's sign (vesicle on tip of nose — indicating nasociliary nerve involvement) predicts ocular complications. Requires urgent ophthalmological evaluation.

VZIG (Varicella-zoster immunoglobulin)
WHO EMLPost-exposure prophylaxis for high-risk seronegative individuals exposed to VZV — given within 96 hours. High-risk groups requiring VZIG: immunocompromised patients; pregnant women; premature neonates; and neonates whose mothers develop varicella 5 days before to 2 days after delivery. Reduces severity rather than preventing infection in most cases.