Protection by Immunisation

Understanding Immunisation

Immunisation refers to the process where the human body is made immune or resistant to an infectious disease, typically by the administration of a vaccine.
A vaccine stimulates the body’s own immune system to protect the person against subsequent infection or disease.
Vaccines are usually administered via needle injections, but can also be administered by mouth or sprayed into the nose.

Vaccines contain antigens that mimic the disease-causing organism. The antigens are weakened or dead forms of the organism, that when injected or ingested, do not cause the disease but stimulate an immune response.
The immune system recognises these antigens as foreign, and responds by producing antibodies, proteins that fight off the foreign invaders.
Memory cells are also produced during this process. These cells remember the specific antigens, leading to a quicker and stronger response if the body encounters the same antigens in the future.

Vaccination is a safe and effective way to protect people from harmful diseases before they come into contact with them.
It not only protects individuals, but also others in the community by reducing the spread of preventable diseases – often referred to as herd immunity.
For some diseases, if enough people are vaccinated, it’s possible to eradicate the disease completely. The most notable example being the global eradication of smallpox in 1979.

Vaccines are thoroughly tested for safety before they’re approved for use, but like any medication, they can have side effects. Most side effects are very mild (like a sore arm or low fever) and go away on their own.
Some people may be allergic to ingredients in a vaccine and have a serious reaction, but this is extremely rare.
There have been controversies around vaccination, most notably the now debunked study linking the MMR vaccine to autism. This has caused some reluctance in vaccine uptake in some communities, leading to outbreaks of preventable diseases. It’s important to consult reliable sources when researching about vaccines.

The NHS provides a Routine Immunisation Schedule, charting when and which immunisations are recommended throughout a person’s life.
For most vaccines to be effective, more than one dose is necessary. These additional doses are called boosters.
Some vaccines are not suitable for certain groups of people, like pregnant women or people with certain medical conditions. Special schedules or precautions may be needed in these cases.