Understanding the Increased Risk with Age
Shingles, or herpes zoster, is a reactivation of the varicella-zoster virus (VZV), the same virus that causes chickenpox. After a person has chickenpox, the virus remains dormant in their nerve cells for the rest of their life. For reasons not fully understood, the virus can reactivate decades later, causing the distinctive and often painful shingles rash. The primary driver for this reactivation is the natural decline of the immune system's effectiveness as we age, a process known as immunosenescence.
The Data: Annual Incidence for 70-Year-Olds
While finding an exact figure for a single year of age can be challenging, reliable studies have provided a clear picture for age groups. Data from sources like the Australian Immunisation Handbook, corroborated by other studies, indicate that the annual incidence rate for people aged 70 to 79 is significantly higher than for younger cohorts. Specifically, the rate is estimated at 1,531 cases per 100,000 population per year for this age bracket.
To translate this figure to a percentage, you can perform a simple calculation: (1,531 / 100,000) * 100, which equals 1.531%. So, while not a cumulative risk, this statistic indicates that in any given year, approximately 1.5% of people in their 70s can expect to develop shingles. This is a dramatic increase from the rates seen in younger populations, which can be less than 1% annually.
Factors Contributing to Heightened Risk
Beyond just age, several other factors can weaken the immune system and further increase the likelihood of a shingles outbreak in older adults.
- Chronic Health Conditions: Illnesses such as diabetes, chronic kidney disease, and lung disease can compromise immune function, putting individuals at higher risk.
- Immunosuppressive Medications: Taking steroids or other medications that suppress the immune system can lower the body's ability to keep the virus dormant.
- High Stress Levels: Periods of prolonged or intense stress can temporarily suppress the immune system, potentially triggering a shingles episode.
- Previous Shingles Episode: Although a rare occurrence, it is possible to get shingles more than once.
Shingles Risk Comparison by Age
This table illustrates how the annual incidence rate of shingles steadily increases with age. The data underscores the critical period of vulnerability for older adults.
| Age Group | Approximate Annual Incidence Rate (per 100,000) | Approximate Annual Percentage Risk |
|---|---|---|
| 50–59 years | 630 | 0.63% |
| 60–69 years | 1,366 | 1.37% |
| 70–79 years | 1,531 | 1.53% |
| 80 years and older | 1,278+* | 1.28%+* |
*Note: Data for those 80+ varies, but consistently remains high, with sources suggesting around 50% will experience shingles by age 85.
The Threat of Postherpetic Neuralgia (PHN)
One of the most serious complications of shingles is a painful condition called postherpetic neuralgia (PHN), where nerve pain persists for months or even years after the rash has healed. The risk and severity of PHN also increase significantly with age. For example, studies show that roughly 1 in 5 shingles cases in people over 80 lead to PHN, compared to about 1 in 10 in the 50-59 age group. This painful and disruptive complication is one of the most compelling reasons for older adults to take proactive measures against shingles.
Prevention Through Vaccination
Given the high incidence and risk of severe complications, vaccination is the single most effective preventive measure. The Centers for Disease Control and Prevention (CDC) recommends that healthy adults aged 50 years and older get two doses of the recombinant shingles vaccine (Shingrix), separated by two to six months.
- High Efficacy: Studies have shown that for people aged 70 and older, the vaccine is highly effective at preventing shingles.
- Reduces Complications: Even if a vaccinated person does get shingles, the vaccine can substantially reduce the risk and severity of complications like PHN.
- Medicare Coverage: In the U.S., Medicare covers the cost of the Shingrix vaccine for older adults enrolled in the program.
For more detailed information on vaccination guidelines and recommendations, the CDC's official resources are invaluable. Visit the CDC's page on shingles for healthcare professionals.
Conclusion
The incidence rate of shingles in the 70s age group is not a rare occurrence, with approximately 1.5% of individuals experiencing it annually. This heightened risk, coupled with the increased potential for severe and long-lasting complications like postherpetic neuralgia, makes shingles a significant concern for seniors. Fortunately, modern vaccines offer a highly effective and safe method of prevention, underscoring the importance of vaccination as a key component of healthy aging.
