Immunization is the process whereby a person is made immune or resistant to an infectious disease, typically by the administration of a vaccine. Vaccines stimulate the body’s own immune system to protect the person against subsequent infection or disease.
Immunization is a proven tool for controlling and eliminating life-threatening infectious diseases and is estimated to avert between 2 and 3 million deaths each year. It is one of the most cost-effective health investments, with proven strategies that make it accessible to even the most hard-to-reach and vulnerable populations. It has clearly defined target groups; it can be delivered effectively through outreach activities; and vaccination does not require any major lifestyle change.
WHICH IMMUNIZATIONS DO MY CHILDREN NEED?
Because proof of immunization is often a prerequisite for enrollment in school or day care, it’s important to keep your children up to date on their vaccines. The benefit of doing so is that your children will be protected from diseases that could cause them serious health problems.
The recommended immunizations for children 0-6 years of age include:
- Hepatitis B
- Diphtheria, tetanus, pertussis
- Haemophilus influenzae type B
- Measles, mumps, rubella
- Varicella (chickenpox)
- Hepatitis A
- Meningococcal (for certain high-risk groups)
WHY SHOULD SOMEONE GET IMMUNIZED?
The goal of public health is to prevent disease. It’s much easier and more cost-effective to prevent a disease than to treat it. That’s exactly what immunizations aim to do.
Immunizations protect us from serious diseases and also prevent the spread of those diseases to others. Over the years immunizations have thwarted epidemics of once common infectious diseases such as measles, mumps, and whooping cough. And because of immunizations we’ve seen the near eradication of others, such as polio and smallpox.
Some vaccines need to be given only once; others require updates or “boosters” to maintain successful immunization and continued protection against disease.
PASSIVE AND ACTIVE IMMUNIZATION
Active immunization can occur naturally when a person comes in contact with, for example, a microbe. The immune system will eventually create antibodies and other defenses against the microbe. The next time, the immune response against this microbe can be very efficient; this is the case in many of the childhood infections that a person only contracts once, but then is immune.
Artificial active immunization is where the microbe, or parts of it, are injected into the person before they are able to take it in naturally. If whole microbes are used, they are pre-treated.
The importance of immunization is so great that the American Centers for Disease Control and Prevention has named it one of the “Ten Great Public Health Achievements in the 20th Century”. Live attenuated vaccines have decreased pathogenicity. Their effectiveness depends on the immune systems ability to replicate and elicits a response similar to natural infection. It is usually effective with a single dose. Examples of live, attenuated vaccines include measles, mumps, rubella, MMR, yellow fever, varicella, rotavirus, and influenza (LAIV).
Passive immunization is where pre-synthesized elements of the immune system are transferred to a person so that the body does not need to produce these elements itself. Currently, antibodies can be used for passive immunization. This method of immunization begins to work very quickly, but it is short lasting, because the antibodies are naturally broken down, and if there are no B cells to produce more antibodies, they will disappear.
Passive immunization occurs physiologically, when antibodies are transferred from mother to fetus during pregnancy, to protect the fetus before and shortly after birth.
Artificial passive immunization is normally administered by injection and is used if there has been a recent outbreak of a particular disease or as an emergency treatment for toxicity, as in for tetanus. The antibodies can be produced in animals, called “serum therapy,” although there is a high chance of anaphylactic shock because of immunity against animal serum itself. Thus, humanized antibodies produced in vitro by cell culture are used instead if available.