Because certain viruses and bacteria evolve to become resistant to the old vaccines.
Vaccines changed society because with out vaccines then there would be so many deaths. Vaccines help to prevent the disease before you get it. Why pay a visit to the doctor when you can just go get the vaccine and not have to get the disease.
There are oral vaccines and injectable vaccines.
By when people have them they stop you from getting the illness so less people have been getting diseases because of the vaccines
Live vaccines are vaccines which are prepared from living organisms. These vaccines are commonly ingested and not injected to fight viruses in the body. .
Vaccines made with "killed" viruses are called "Inactivated" vaccines.
They are vaccines that have a live microbe but it has been changed in some way, Here is a list of those: Tuberculosis (BCG), Oral Polio Vaccine, Measles, Rotavirus, and Yellow Fever. They can and have revered back to one that are disease causing.
Edible vaccines are vaccines produced in plants genetically modified through bioengineering.
it has changed in the world
Vaccines don't actually treat either one. Vaccines are used to PREVENT disease. Most vaccines protect against viruses, but there are some for bacteria, as well.
The invention of the gun changed the world. You could also say that telescopes/microscopes changed the world.
It has changed our world in many ways: - computers - phones - medicine - MOST IMPORTANTLY....ALL MEDICAL TOOLS, TREATMENTS, AND PROCEDURES! I can't tell you how thankful our world should be because of technology and how it has shaped the medical world! :) - Vaccines - email - online chat-rooms - ALL OF SCIENCE! AND ALL OF SCIENTIFIC TOOLS, AND LAB EXPERIMENTS! - facebook - telephone calling - TV - HD - AND ANYTHING ELSE THAT WAS NOT INVENTED IN THE FIFTIES! LOL!
Vaccines are good for us!!
Vaccines do not cause AIDS.
The most recent vaccines to come out, is the H1N1 aka SWINE FLU vaccines.
it has changed most of the world
The World changed fashion
How much money are horse vaccines
You should have vaccines so you don't get sick
Flu vaccines are stored in the refrigerator.
He changed the world by solving problems.
Radium and polonium doesn't changed the world.