Zostavax

Zostavax was a live attenuated vaccine developed and marketed by Merck & Co. to reduce the risk of herpes zoster, commonly called shingles, and certain complications associated with the disease. It used a weakened form of varicella-zoster virus derived from the Oka strain and was administered as a subcutaneous injection. Unlike routine childhood varicella vaccination, which is intended to prevent primary chickenpox infection, Zostavax was designed primarily to boost waning immunity to varicella-zoster virus in older adults who remained at risk of reactivation as shingles. The vaccine became one of the first widely used preventive products specifically directed at shingles. The United States Food and Drug Administration approved it in 2006 for adults aged 60 years and older. The US indication was later expanded to include adults aged 50 years and older. Other regulators authorized the product for age groups and schedules that varied by jurisdiction. In the United States, the recommended regimen was generally one dose for eligible adults, while some markets used different age recommendations or reimbursement arrangements. Zostavax occupied an important position in Merck's vaccine portfolio during the period before recombinant shingles vaccination became available. Its principal clinical value was a reduction in the incidence of shingles and postherpetic neuralgia rather than complete elimination of the risk of disease. Protection was also understood to decline over time, an issue that became increasingly relevant as more durable alternatives entered the market. The competitive environment changed substantially after GlaxoSmithKline's Shingrix, a non-live recombinant zoster vaccine, was approved in the United States in 2017. Shingrix demonstrated higher and more persistent efficacy across older age groups and was recommended by the US Centers for Disease Control and Prevention in preference to Zostavax. In the United States, Merck discontinued distribution of Zostavax in 2020, and the product was subsequently withdrawn or discontinued in additional markets. The US product was no longer available for routine vaccination after remaining inventory expired or was removed from distribution. Zostavax is therefore a discontinued pharmaceutical product rather than an active vaccine brand in the United States. Its historical significance lies in establishing adult shingles vaccination as a major preventive-health category, while its commercial decline illustrates the effect of a newer vaccine with stronger efficacy, a non-live platform, and a preferred public-health recommendation. Merck remains the product's original developer and manufacturer, but Zostavax is not a current alternative to recombinant zoster vaccination where newer products are available.

Zostavax was developed by Merck as a vaccine for prevention of herpes zoster, a painful reactivation of varicella-zoster virus that becomes more common with age and immune decline. The product used a live attenuated Oka/Merck strain of varicella-zoster virus. Its scientific rationale was to strengthen virus-specific immunity in adults whose protection from earlier chickenpox infection had diminished over time. The US Food and Drug Administration approved Zostavax in 2006 for adults aged 60 years and older. This made it one of the first broadly deployed vaccines specifically intended to prevent shingles in older adults. The initial US label focused on reducing the incidence of herpes zoster, while clinical evidence also supported a reduction in postherpetic neuralgia, a persistent nerve-pain complication. The vaccine was administered as a single subcutaneous dose in the US program. Regulatory approvals and recommendations in other countries varied according to local evidence, age thresholds, immunization policies, and reimbursement systems. Merck's product became part of the expanding adult-immunization market. Its use was directed toward people with a history of chickenpox or latent varicella-zoster infection, rather than toward primary prevention of chickenpox in children. Because it was a live vaccine, labeling included restrictions and precautions for certain immunocompromised people, pregnant people, and others for whom live-virus vaccination could present additional risk. Zostavax also had limitations in durability and effectiveness across age groups, with protection tending to decline over time. In 2011, the FDA approved an expanded US indication for adults aged 50 through 59. This broadened the commercially addressable population, although public-health recommendations and insurance coverage did not always align identically with the product's regulatory label. During this period, Zostavax remained a significant Merck vaccine brand and was used in several international markets under local regulatory frameworks. The product's competitive position changed after GlaxoSmithKline introduced Shingrix, a recombinant, adjuvanted zoster vaccine. Shingrix was approved in the United States in 2017 and subsequently received a strong recommendation from the CDC's Advisory Committee on Immunization Practices. The newer vaccine showed substantially higher efficacy against shingles and postherpetic neuralgia than Zostavax in the studied older-adult populations, and its non-live platform made it suitable for many people for whom a live vaccine was inappropriate. In 2018, the CDC recommended Shingrix over Zostavax for routine prevention in immunocompetent adults aged 50 and older and for adults previously vaccinated with Zostavax. As demand moved toward Shingrix, Merck ended US distribution of Zostavax in 2020. The product was also discontinued or withdrawn in additional countries over the following period, with exact timing depending on local supply and regulatory arrangements. Zostavax consequently became a discontinued brand in the United States. Its legacy is both clinical and commercial: it helped establish shingles vaccination as a standard adult-prevention category, but it was ultimately displaced by a newer vaccine with higher and more durable protection and a broader suitability profile.

• 2020

  US distribution discontinued

  [4]Merck announcement on US Zostavax discontinuationmerck.com

  Merck announced the discontinuation of Zostavax distribution in the United States as demand shifted to Shingrix.

• 2018

  CDC preference changes to Shingrix

  [3]CDC clinical overview of Shingrix and shingles vaccinationcdc.gov

  The CDC recommended Shingrix in preference to Zostavax for routine vaccination of eligible adults and recommended revaccination with Shingrix for people previously vaccinated with Zostavax.

• 2017

  Recombinant competitor enters the US market

  [5]Recombinant competitor enters the US marketfda.gov

  FDA approval of Shingrix introduced a newer recombinant zoster vaccine that later became the preferred US option over Zostavax.

• 2011

  Expanded US age indication

  [2]FDA Zostavax informationfda.gov

  The FDA expanded the US indication to adults aged 50 through 59.

• 2006

  US approval

  [1]FDA approval announcement for Zostavaxfda.gov

  The FDA approved Zostavax for prevention of herpes zoster in adults aged 60 years and older.

Formerly positioned as an adult vaccine for prevention of herpes zoster and reduction of postherpetic neuralgia risk, especially among older adults.

• Live attenuated herpes zoster vaccine · 2006

  Zostavax

  Zostavax was a single-dose, subcutaneous live attenuated vaccine based on the Oka/Merck strain of varicella-zoster virus. It was designed to reduce the risk of shingles and postherpetic neuralgia in older adults. The product was approved in the United States for adults aged 60 and older in 2006, with the US indication expanded to adults aged 50 and older in 2011. It was later displaced by recombinant zoster vaccination and discontinued in the United States.

• 2020

  Discontinue US distributionStrategy

  Background

  The launch and strong public-health recommendation of Shingrix shifted the shingles-vaccine market toward a newer recombinant product.

  Action taken

  Merck announced that it would discontinue distribution of Zostavax in the United States.

  Aftermath

  Zostavax ceased to be a routine US shingles-vaccination option, leaving Shingrix as the CDC-preferred product.

  • GlaxoSmithKline Shingrix — Shingrix became the preferred US shingles vaccine after recommendations emphasized its higher efficacy and broader suitability.

  Source

• 2011

  Expand the US age indicationOther

  Background

  The original US authorization covered adults aged 60 years and older, while younger adults also faced a clinically meaningful risk of shingles.

  Action taken

  Merck obtained FDA approval to market Zostavax for adults aged 50 through 59.

  Aftermath

  The decision broadened the labeled population, although later US public-health recommendations favored Shingrix for eligible adults.

  Source

1. 1FDA approval announcement for Zostavaxfda.gov
2. 2FDA Zostavax informationfda.gov
3. 3CDC clinical overview of Shingrix and shingles vaccinationcdc.gov
4. 4Merck announcement on US Zostavax discontinuationmerck.com
5. 5Recombinant competitor enters the US marketfda.gov