The ingredients found in a vaccine all play an important role in ensuring that the vaccine remains effective and safe. All vaccine ingredients are present in small amounts and occur naturally in the food we eat and in nature.
The main ingredients in a vaccine are dead or weakened viruses or bacteria.
Vaccines may also contain:
- Adjuvants: to help the body's immune system respond better to the vaccine.
- Additives and preservatives: to help preserve the quality and effectiveness of the vaccine.
Additives and preservatives are added to vaccines to maintain their quality and effectiveness. Here are some examples of ingredients that may be found in vaccines and the reasons why they are added.
Additives
These allow vaccines to remain effective during storage.
Example: Gelatin
Some vaccines contain gelatin to protect them from freeze-drying or heat. Gelatin is also used as a stabilizer in live vaccines. However, the use of gelatin as an additive in vaccines has decreased, although the incidence of allergic reactions is currently very low.
Preservatives
Prevent contamination of vaccine vials.
