Adult Vaccination:
Beyond Childhood

1. Introduction: The Myth of "Childhood Vaccines"

There is a widespread misconception that vaccines are exclusively for pediatrics. Many adults believe that once they complete the childhood schedule, they are protected for life. However, acquired immunity against many diseases declines over time (waning immunity), and new risks emerge with aging.

Vaccine-preventable diseases, such as flu, pneumonia, and herpes zoster, are leading causes of morbidity, hospitalization, and death in adults over 50. Keeping vaccination records up to date is one of the most cost-effective health interventions for healthy longevity.

2. Immunosenescence: Why Does the Immune System Age?

With advancing age, the immune system undergoes a natural process of functional deterioration called Immunosenescence. Key features include:

• Thymus Involution: The organ where T cells mature atrophies, reducing the production of new virgin (naïve) cells capable of recognizing new antigens.
• Inflammaging: A state of chronic low-grade inflammation that dysregulates the immune response.
• Failing Immunological Memory: Existing memory cells become less effective, requiring more potent or frequent booster doses to reactivate protection.

3. Herpes Zoster: The Fire of St. Anthony (Shingles)

The Varicella-Zoster virus (the same as chickenpox) remains latent in the spinal nerve ganglia of almost all adults. When cellular immunity drops (due to age or stress), the virus reactivates, traveling along the nerve to the skin, causing Herpes Zoster (Shingles).

The Threat of Postherpetic Neuralgia

The skin rash is painful, but the most feared complication is Postherpetic Neuralgia (PHN): excruciating neuropathic pain that can persist for months or years after the skin lesions heal, devastating quality of life.

The New Recombinant Vaccine (Shingrix)

Unlike the old vaccine (live attenuated virus), the new recombinant vaccine (glycoprotein E + adjuvant) offers efficacy greater than 90% even in elderly people over 70. It is recommended for everyone over 50, regardless of whether they have had chickenpox or zoster previously.

4. Pneumococcal Pneumonia: The "Captain of Death"

The bacterium Streptococcus pneumoniae (pneumococcus) is the leading cause of bacterial pneumonia, meningitis, and sepsis in the elderly. Mortality from Invasive Pneumococcal Disease rises sharply after age 60.

Sequential Schedule

Medical societies recommend a combined schedule for maximum protection:

1. PCV13 or PCV15 (Conjugate): Generates robust immunological memory and mucosal protection.
2. PPSV23 (Polysaccharide): Broadens the spectrum of protection to more serotypes. Administered 6 to 12 months after the first.

5. Hepatitis B: Not Just a Sexually Transmitted Disease

Although sexual transmission is common, Hepatitis B is also transmitted through unsafe medical/dental procedures, manicures, and sharing personal items. Chronic infection is silent and the leading cause of liver cancer (hepatocarcinoma) worldwide.

Many adults born before the 90s were not vaccinated in childhood. The vaccine is extremely safe and effective, recommended for all non-immune adults, regardless of age.

6. Tetanus, Diphtheria, and Pertussis (Tdap)

The adult double vaccine (Td) protects against tetanus and diphtheria and should be boosted every 10 years. However, replacing one of these boosters with Tdap (which includes protection against Whooping Cough/Pertussis) is crucial.

Pertussis in adults may manifest only as a prolonged cough, but these adults are the main transmitters to newborns, in whom the disease can be fatal. Grandparents and caregivers should take Tdap before contact with the baby.

7. Seasonal: Influenza and COVID-19

Respiratory viruses undergo constant mutations (antigenic drift), requiring annual vaccine updates. Annual flu vaccination reduces the risk of heart attack and stroke in the elderly as much as quitting smoking or taking statins, due to the reduction of systemic inflammation caused by the virus.

8. Adult Vaccination Schedule (Summary)

9. Conclusion

Vaccination in adulthood is an irreplaceable pillar of preventive medicine. It protects against functional decline, prevents catastrophic hospitalizations, and protects future generations. Checking vaccination records should be an integral part of any medical check-up after age 18. Investing in immunization is investing in active longevity.