Vaccine Basics
Vaccines are some of the safest medicines that exist. Every vaccine undergoes a lot of testing before it becomes available, and vaccine safety continues to be monitored the whole time that a vaccine is in use.
Most side effects from vaccines are very minor, such as a sore arm or fever, and they usually don’t last very long. There is a small risk that serious problems could occur after getting a vaccine, but the potential risks from a vaccine-preventable disease are much more serious.
Every vaccine ingredient serves a purpose
To provide immunity
We become immune to (or protected from) a disease when our bodies create specific antibodies to fight that disease. Vaccines contain ingredients that help your body build this immunity.
To keep the vaccine safe and long-lasting
Vaccines need to be safe and effective. Certain ingredients help keep vaccines safe from contamination and toxins. Others, like stabilizers, help vaccines stay effective for a long time.
To make the vaccine more effective
All vaccine ingredients help to make a vaccine as effective as possible, while being safe. Ingredients like aluminum salt help boost the body's response to the vaccine.
Ingredients found in some vaccines
Stabilizers
- Purpose: To keep the vaccine effective after manufacturing
- Most commonly found in: Jell-O®, naturally in the body
- Examples: Sugars, gelatin
Adjuvants
- Purpose: To help boost the body's response to the vaccine
- Most commonly found in: Drinking water, infant formula, and some health products such as antacids, buffered aspirin, and antiperspirants
- Examples: Aluminum salts
Residual inactivating ingredients
- Purpose: To kill viruses or inactivate toxins during the manufacturing process
- Most commonly found in: Naturally in the human body, fruit, household furnishings (carpets, upholstering)
- Example: Formaldehyde
Residual cell culture materials
- Purpose: To grow enough of the virus or bacteria to make the vaccine
- Most commonly found in: Eggs, and foods that contain eggs
- Examples: Egg protein
Residual antibiotics
- Purpose: To prevent contamination by bacteria during the vaccine manufacturing process
- Most commonly found in: Common antibiotics. Antibiotics that people are most likely to be allergic to—like penicillin—aren't used in vaccines.
- Examples: Neomycin, Kanamycin, Streptomycin
Preservatives
- Purpose: To prevent contamination
- Most commonly found in: Some kinds of fish
- Example: Thimerosal (only in multi-dose vials of flu vaccine)
Most vaccines don't contain any mercury
Most vaccines do not have any mercury in them. However, multi-dose flu vaccines and one type of tetanus-diphtheria (Td) vaccine contain a small amount of thimerosal. Thimerosal contains a form of mercury (ethylmercury) that does not cause mercury poisoning and is safe for use in vaccines. Flu and Td vaccines are also available in thimerosal-free versions.
Different types of vaccines work in different ways
Vaccines can help protect against certain diseases by imitating an infection. This helps teach the immune system how to build immunity to fight off a future infection. Different vaccines provide immunity in different ways.
Vaccine information for you and your family
Prenatal vaccines
Getting vaccinated is one of the most important things that you can do to protect your health and your fetus’ health while you are pregnant. Vaccines have been safely given to millions of pregnant people.
After you get a vaccine during pregnancy and your body creates antibodies, some of those antibodies pass to the fetus. This means the baby will have antibodies to protect against disease after birth. Antibodies are a safe, normal reaction to a vaccine. They protect your baby during the first few months of life until your baby can be vaccinated.
Content from the American College of Obstetricians & Gynecologists, available here.
More information about vaccines including information for adults, children and expecting Moms here.
