Developing Immunity

Natural and Artificial Immunity

Natural immunity occurs when you become immune to a specific disease after contracting it, while artificial immunity refers to immunisation through vaccination.

Natural Active Immunity

This type of immunity occurs when the body encounters a pathogen and produces an immune response involving the production of antibodies and memory cells.
Memory cells provide long-term immunity, because they can quickly replicate and produce the necessary antibodies if the pathogen is encountered again.

Natural Passive Immunity

This provides immediate but short-lived protection. It commonly occurs during pregnancy, when antibodies are transferred from the mother to the fetus via the placenta.
Similarly, a newborn baby receives antibodies from the mother through breast milk, providing temporary immunity to diseases the mother is immune to.

Artificial Active Immunity

Vaccines can induce this type of immunity. Vaccines contain weakened or inactive parts of a particular pathogen (antigens) that trigger an immune response.
Vaccines can be either live-attenuated, containing weakened forms of the pathogen, or inactivated containing killed pathogens or fragments of the pathogen.
Like natural active immunity, vaccination leads to the production of memory cells which provide long-term immunity.

Artificial Passive Immunity

This type involves the direct introduction of antibodies into an individual from another source.
For example, a person bitten by a rabid animal might receive a rabies antiserum injection, which contains antibodies against the rabies virus.
This type of immunity gives immediate protection, but the body does not produce memory cells, so the protection is not long-lasting.

The Role of Herd Immunity

Herd immunity describes a form of immunity that occurs when the vaccination of a significant portion of a population provides a measure of protection for individuals who have not developed immunity.
Herd immunity can effectively stop the spread of disease in the community, offering protection to those who cannot be vaccinated, such as newborns, pregnant women, or immune-compromised individuals.

Risks and Ethical considerations of Vaccinations

Vaccines are typically safe and side effects are usually minor. However, complications can happen and it’s important that individuals are aware of the benefits and risks.
Denying vaccination due to personal beliefs or misinformation can foster outbreaks and put others at risk, especially those who are unable to be vaccinated.
Compulsory vaccination raises ethical questions regarding individual liberty and rights. Balancing these ethical concerns with public health interests can be complex and is a matter of continual debate.

Studying immunity can give us insights into the complex interactions of the immune system, and guides the creation of vaccines to help control, prevent, and eradicate infectious diseases.