The Shift from Zostavax to Shingrix
Historically, the shingles vaccine landscape was dominated by Zostavax, a live vaccine using a weakened chickenpox virus. Its effectiveness declined with age, particularly in adults over 80, where studies indicated only about 18% efficacy. This led to age restrictions, often around 79 or 80, in programs in the UK and other regions, creating the misconception that people over 80 are not eligible for the shingles vaccine. Zostavax is no longer available in the United States as of November 2020.
With the introduction of Shingrix, a recombinant, non-live vaccine, the situation changed. Shingrix utilizes a viral protein and an adjuvant to create a robust immune response, effective even in older adults whose immune systems are naturally weaker.
The Recommendation for Shingrix
The CDC recommends two doses of Shingrix for healthy adults aged 50 and older, with no maximum age limit. Clinical trials demonstrate high efficacy in older age groups:
- Adults 50–69 years old: 97% effective.
- Adults 70 years and older: 91% effective.
This high efficacy extends to those in their 80s and 90s, refuting previous age-based restrictions.
The Immune Response and Age
Immunosenescence, the aging of the immune system, contributes to the increased risk of shingles in older adults. Shingrix is formulated with a potent adjuvant to enhance the immune response, helping older adults build strong protection against the virus.
Comparing Shingrix and Zostavax for Older Adults
| Feature | Shingrix (RZV) | Zostavax (ZVL) |
|---|---|---|
| Vaccine Type | Recombinant (Non-live) | Live, Attenuated |
| Primary Target | All adults 50+, including older adults and immunocompromised individuals | Healthy adults 50+, limited use in older adults |
| FDA Approval | October 2017 for adults 50+ | 2006, discontinued in the US in November 2020 |
| Efficacy in 70+ | 91% effective in preventing shingles | 41% effective in preventing shingles |
| Efficacy in 80+ | Efficacy similar to 70+ group | 18% effective in preventing shingles |
| Maximum Age | No maximum age limit | Age restrictions common due to low efficacy and live virus risk |
| Dosing | Two doses, 2 to 6 months apart | Single dose |
Addressing Past Misinformation and Confusion
Outdated policies, like the UK program from 2013 that restricted eligibility at age 79, were based on the limitations and supply of the older vaccine. These restrictions are now obsolete due to Shingrix's superior performance and availability. The current standard from organizations like the CDC supports vaccination for adults 50 and older with no upper age limit. Anyone previously deemed too old for Zostavax should consult their doctor about receiving Shingrix, as they are now eligible and can greatly benefit from its protection.
Conclusion: No Upper Age Limit
The belief that people over 80 are not eligible for the shingles vaccine is based on outdated information about Zostavax. The current vaccine, Shingrix, is highly effective for adults 50 and older, including those over 80, with no recommended upper age limit. Shingrix's superior efficacy and non-live composition make it the preferred vaccine. Individuals who were previously ineligible due to age should consult a healthcare provider about getting Shingrix to prevent shingles and its potential complications like postherpetic neuralgia.
Outbound Link
For more information on shingles and the vaccine recommendations, please visit the official website of the Centers for Disease Control and Prevention at https://www.cdc.gov/shingles/vaccines/index.html.
