BCG (Bacille Calmette-Guérin) vaccination is generally not given to individuals over the age of 35. While it is rarely administered to anyone over the age of 16, 35 years old marks the absolute upper age limit for receiving the vaccine.
Understanding BCG Vaccination Ages
The BCG vaccine is primarily given to infants and young children to protect them from severe forms of tuberculosis (TB). Its effectiveness significantly diminishes in older individuals, leading to specific age cut-offs for its administration.
- Infancy and Childhood: This is the primary target group for BCG vaccination in countries where TB is prevalent or for children at high risk.
- Teenagers (16 years and under): It is uncommon to give the BCG vaccine to individuals over 16.
- Adults (16 to 35 years): While generally not given over 16, there are specific circumstances where adults between 16 and 35 years of age might receive the BCG vaccine. These are typically individuals at an increased risk of TB exposure through their work, such as some healthcare professionals, or those with prolonged contact with an active TB case.
- Adults Over 35: The BCG vaccine is never given to individuals over the age of 35.
Why the Age Limit of 35?
The primary reason for the age limit is the significantly reduced efficacy of the BCG vaccine in older adults. Studies and clinical experience have shown that the vaccine does not work very well in individuals over 35. Administering it beyond this age would not offer sufficient protection against tuberculosis and is therefore not recommended.
Who Might Still Receive BCG After Childhood?
Even with the general guideline of not giving BCG over 16, certain at-risk groups between the ages of 16 and 35 may still be eligible. These include:
- Healthcare Workers: Individuals working in healthcare settings who are at a higher risk of occupational exposure to TB.
- Laboratory Personnel: Those who handle mycobacteria (the bacteria causing TB).
- Individuals with Close Contact: People who have had prolonged, close contact with a person who has active pulmonary TB and are not protected by prior vaccination or infection.
- Travelers: People planning to live or work in countries with high rates of TB for an extended period, particularly if they will be exposed to populations at high risk of TB.
BCG Vaccination Guidelines by Age
For clarity, here's a summary of the general guidelines regarding BCG vaccination across different age groups:
| Age Group | BCG Vaccination Guideline | Reason |
|---|---|---|
| Infants & Young Children | Recommended, especially in high-prevalence areas or for at-risk individuals. | Highest efficacy and protection against severe forms of TB. |
| Over 16 years old | Rarely given. | Decreased effectiveness in older individuals. |
| 16 to 35 years old | Considered only for specific high-risk occupational or exposure groups. | Limited efficacy; targeted protection for specific risks. |
| Over 35 years old | Never given. | Minimal to no proven efficacy in this age group. |
For more detailed information on BCG vaccination guidelines, it is always recommended to consult official public health resources:
