Vaccines contain weakened or inactive parts of a particular organism (antigen) that triggers an immune response in the body. Newer vaccines contain the pattern of antigen production rather than the antigen itself. Whether the vaccine is made up of the antigen itself or the pattern for the body to make the antigen, this weakened version will not cause illness in the vaccinated person, but it will make their immune system respond as much as it does. . it would have during its first reaction to the actual pathogen.
Some vaccines require multiple doses, weeks or months apart. This is sometimes necessary to allow the production of long-lived antibodies and the development of memory cells. In this way, the body is trained to fight the specific pathogen organism, building the memory of the pathogen in order to fight it quickly in the event of future exposure.
When a person is vaccinated, it is very likely that they will be protected against the targeted disease. But not everyone can be vaccinated. People with underlying health problems that weaken their immune systems (such as cancer or HIV) or who have severe allergies to some vaccine components may not be able to get vaccinated with some vaccines. These people can still be protected if they live and among others who are vaccinated. When a large number of people in a community are vaccinated, the pathogen has difficulty circulating because most of the people it encounters are immune. Thus, the more others are vaccinated, the less people who may not be able to be protected by vaccines will be exposed to harmful pathogens. This is called collective immunity.
This is especially important for people who not only cannot be vaccinated, but may be more susceptible to the diseases we are vaccinating against. No vaccine provides 100% protection, and herd immunity does not provide complete protection for those who cannot be safely vaccinated. But with collective immunity, these people will benefit from substantial protection, thanks to the vaccination of those around them.
Vaccination not only protects you, but also protects community members who cannot be vaccinated. If you are able, get vaccinated.
The body has many ways of defending itself against pathogens (pathogens). Skin, mucus, and cilia (microscopic hairs that keep debris away from the lungs) all act as physical barriers to prevent pathogens from entering the body in the first place.
When a pathogen infects the body, our body’s defenses called the immune system are triggered and the pathogen is attacked and destroyed or overcome.