BASIC CONSIDERATIONS

The term immunity in preventive pediatrics refers to complete protection or at least partial resistance against an infection, and may be classified as:

• Natural immunity, acquired by:

- Transplacental transfer of maternal antibodies in fetal life, i.e.

- Clinical or sub-clinical infections in postnatal life, i.e. natural active immunity.

• Artificial immunity, acquired by:

- Disease-specific vaccinations, i.e. artificial active immunity, or

- Administration of specific or non-specific immuno­globulins, i.e. artificial passive immunity.

While active immunity persists for many years or even throughout the life, passive immunity does not last for more than few weeks. This chapter concentrates on artificial immunity, specially active immunization via vaccines, followed by some relevant aspects of passive immunization.

9.1.1