Let's talk vaccines: ᴵᵐᵐᵘⁿⁱᵗʸ

The immune system could be its own series, there's so much to talk about in regards to it. But we aren't going to go *there* so here's some basic info about the immune system as it pertains to our look at vaccines.

There are three types of immunity: innate, adaptive (also called active or acquired), and passive.

Innate immunity is what we are all born with. We are all born with some level of immunity to invaders. Human immune systems, similarly to those of many animals, will attack foreign invaders from day one. This innate immunity includes the external barriers of our body — the first line of defense against pathogens — such as the skin and mucous membranes of the throat and gut.

Active immunity results when exposure to an antigen triggers the immune system to produce antibodies to that disease. Exposure to the disease can occur through infection with the actual disease (resulting in natural immunity), or introduction of a killed or weakened form of the disease through vaccination. Active immunity is long-lasting, and sometimes life-long.

Passive immunity is provided when a person is given antibodies to a disease rather than producing them through his or her own immune system. A newborn baby acquires passive immunity from its mother through the placenta. A person can also get passive immunity through antibody-containing blood products such as immune globulin. Passive immunity lasts only for a few weeks or months.

Vaccines are also called immunizations because it introduces antigens or weakened pathogens to a person in such a way that the individual does not become sick but still produces antibodies. Because the body saves copies of the antibodies, it is protected if the threat should reappear later in life, therefore putting the person in a state of active immunity.

Some people believe that naturally acquired immunity—immunity from having the disease itself—is better than the immunity provided by vaccines. However, natural infections can cause severe complications and be deadly. This is true even for diseases that many people consider mild, like chickenpox. It is impossible to predict who will get serious infections that may lead to hospitalization.

A white blood cell (yellow) is shown here eating an anthrax bacteria (orange).
The white line in the bottom left-hand corner of the slide denotes a 5 micrometer
(one MILLIONTH of a meter) measurement.

{You can find all the sources I used by clicking here.}