vaccines contain either live or killed antigen .live vaccines contain attenuated (weakened)viruses which do not have the ability to cause disease.when the vaccine is injected the body produces anti-bodies against it .next time when the virus enters by that time the body has enough anti-bodies to fight the disease causing virus successfully.
The vaccination is basically a deactivated virus or something that simulate the virus, so it tricks your body into thinking that you have the virus. Your body then produces antibodies through cells called b cells and attacks the virus with cells called t cells. On your first encounter with the virus, it may take a while to find these cells in your body, because you only have one of each, bu once they are found they produce antibodies and attack the virus. Once the virus is eliminated, the b and t cells quickly dissapear, but there are memory b and t cells that stay in the body so that a second encounter with the virus is responded to and eliminated quickly by these memory cells. So the idea of vaccines are to create these memory cells by tricking your body so that If you really encounter the disease, It is quickly eradicated.
It may be called:
Immune response or Adaptive response (since the immune system adapts to produce the antigens to fight the disease when exposed to the vaccine).
Babies are vaccinated to protect against common diseases until their immune systems are developed.
An immune response is part of the body's defense against pathogens in which cells of the immune system react to each kind of pathogen with a defense targeted specifically toward that pathogen.
Vaccination is the process of attempting to confer artificial immunity on an individual organism by exposing the immune system to antigens of the pathogen being vaccinated against. Vaccination does not provide nearly as good protection as natural, or acquired immunity.
Yes.
Ideally a person would never contract a disease that he/she has been vaccinated against. The foundation of vaccination is the idea that you expose a person's immune system to the pathogen that causes a disease so that the immune system will recognize it and kill it off quickly if the person is ever exposed again. In reality, some vaccinations just don't work - there are always a few people that don't respond to the vaccine, or that respond weakly and don't have enough memory cells to fight off the pathogen.
True
Immunity is directed against a particular pathogen.
An allergic reaction i believe.
Active acquired immunity occurs when you get an infection by a pathogen (bacteria, virus) and your body responds and removes the pathogen and also your body makes "memory" cells. These cell remember this pathogen and when it enters your body again you remove it immediately. You are now immune to it. You usually don't notice this.
You get immunity by having a vaccination or by having the infection itself. The vaccination is the introduction of the pathogen in tiny amounts to kick start your immune system so it knows how to deal with the real thing if you encounter the germ in the environment. A vaccine is the medicine made to introduce the pathogen (infection-causing "bug") into your body in a vaccination. Having immunity is how your body prevents a second infection by the same germ. The first time you catch the germ (or get a vaccination for it), your body responds to cause immunity, so if you run across the same exact germ again later, your body already knows how to prevent an infection again. See the related questions below for more about vaccines and vaccinations.
a weaker/dead form of the pathogen is introduced to allow the body to produce the correct antibodies and make a memory-B cell that stimulates a faster immune response if the same pathogen is encountered a second time, preventing a full scale infection and making you "immune" to that pathogen
When you are vaccinated, your body builds up an immune response to the vaccination. This protects you from the disease you were vaccinated for. There is some controversy about vaccination.