Infectious Diseases II – Infection Control
by Medic-CE Staff

Infectious Disease Prevention: Immunizations

Introduction:

Immunizations are the cornerstone of infectious disease prevention. Knowledge of the various types of immunizations is not only important for your personal well-being, but also for educating the public as a whole. Few advances in healthcare have resulted in as big an impact on decreasing morbidity and mortality as the administration of routine vaccinations. The following section will present a detailed, but concise, description of the types of vaccinations available, as well as the rationale for their use, the timing of administration, and other related information.

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Types:

-Active Immunization:

Active immunization includes live vaccines and non-live vaccines.

-Live Vaccines: Live active vaccination involves the injection of a modified live pathogen into the body, which can stimulate an immune reaction with the production of antibodies, without actually causing disease. This type of vaccination is the most likely to induce long-term immunity. However, an important consideration is that live vaccines carry a slight risk that the attenuated pathogens can still cause disease. Consequently, they should be avoided in immunocompromised individuals. Examples include: the oral polio vaccine (OPV for short), varicella vaccine (for chicken pox), and the combined measles/mumps/rubella vaccination.

-Non-Live Vaccines: The non-live vaccinations are preparations that contain killed microbes of virulent strains. They induce immunity which is of a shorter duration than live vaccines and may require a booster. Examples include: the Hepatitis A and B vaccines, the inactivated polio vaccine (IPV for short), the combined diphtheria/tetanus/acellular pertussis vaccine, as well as the pneumococcal and meningococcal vaccinations.

-Passive Immunization:

Passive immunization involves the delivery of preformed antibodies to an individual who has been exposed to or is at high risk for exposure to a pathogen. Examples include: Hepatitis B immunoglobulin, Rh immunoglobulin (known as Rhogam®), and the varicella zoster immunoglobulin.

Side Effects of Immunization:

The most common side effects are only mild to moderate in severity and are characterized by low grade fevers and some local inflammation at the site of injection within the first 24 hours. Also, some live vaccines can cause a rash that may occur 1 to 2 weeks after immunization. Fortunately, serious side effects are exceedingly rare.

Special Notes:

-Immunodeficient patients should not receive the oral polio, MMR, or varicella vaccinations.

-Pregnant patients should not receive live vaccines.

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