What do vaccine contain?
What do vaccine contain?
These are the parts of the vaccine made from viruses or bacteria (also called ‘antigens’). They challenge the immune system so that it makes antibodies to fight the disease. Vaccines contain tiny quantities of active ingredients – just a few micrograms (millionths of a gram) per vaccine. To give some idea of how small these quantities are, one paracetamol tablet contains 500 milligrams of the drug. This is several thousand times more than the quantity of the active ingredient you would find in most vaccines. Hundreds of thousands of individual vaccines could be made from a single teaspoon of active ingredient.
Some vaccines contain whole bacteria or viruses. In these cases the bacteria or viruses will either be severely weakened (attenuated) so that they cannot cause disease in healthy people, or killed altogether (inactivated). Many vaccines contain only parts of viruses or bacteria, usually proteins or sugars from the surface. These stimulate the immune system but cannot cause disease.
Compared to the number of viruses and bacteria in the environment that our bodies have to deal with every day, the amount of active ingredient in a vaccine is very small indeed. Most bacterial vaccines contain just a few proteins or sugars from the relevant bacterium. By contrast it is estimated that 100 trillion bacteria live on the skin of the average human being, each of them containing many thousands of proteins which constantly challenge our immune systems.
These are the parts of the vaccine made from viruses or bacteria (also called ‘antigens’). They challenge the immune system so that it makes antibodies to fight the disease. Vaccines contain tiny quantities of active ingredients – just a few micrograms (millionths of a gram) per vaccine. To give some idea of how small these quantities are, one paracetamol tablet contains 500 milligrams of the drug. This is several thousand times more than the quantity of the active ingredient you would find in most vaccines. Hundreds of thousands of individual vaccines could be made from a single teaspoon of active ingredient.
Some vaccines contain whole bacteria or viruses. In these cases the bacteria or viruses will either be severely weakened (attenuated) so that they cannot cause disease in healthy people, or killed altogether (inactivated). Many vaccines contain only parts of viruses or bacteria, usually proteins or sugars from the surface. These stimulate the immune system but cannot cause disease.
Compared to the number of viruses and bacteria in the environment that our bodies have to deal with every day, the amount of active ingredient in a vaccine is very small indeed. Most bacterial vaccines contain just a few proteins or sugars from the relevant bacterium. By contrast it is estimated that 100 trillion bacteria live on the skin of the average human being, each of them containing many thousands of proteins which constantly challenge our immune systems.
