Diphtheria
A highly contagious and sometimes fatal bacterial disease that causes mucous membrane inflammation, making breathing and swallowing difficult. Diphtheria can also cause swelling of the heart and nerves.
Contraindication
A condition which makes a particular treatment or procedure inadvisable. For example, someone undergoing chemotherapy may be advised to wait on some vaccines, particularly live viral vaccines.
Conjugate vaccine
The addition of a compound (e.g., a sugar or a protein) to an antigen that increases a vaccine’s effectiveness.
Community immunity
Community immunity happens when enough people in a community are immune to a disease that they “shield” those who don’t have immunity from getting the disease. This immunity can come from the disease itself but that means that a lot…
Communicable
A disease that can be passed from one person or animal to another.
Combination vaccine
Combination vaccines take two or more vaccines that could be given individually and put them into one shot or oral dose.
Chronic health condition
An illness or injury that lasts for a long period of time (e.g., cancer, asthma).
Causal association
A relationship between two things where one thing makes a change in the other one happen. For instance, smoking has a causal association with lung cancer.
Breakthrough infection
When a person gets sick with the disease despite having been vaccinated against it. Breakthrough infections are uncommon but no vaccine is 100% effective.
Booster shots
Additional doses of a vaccine needed periodically to remind the immune system how to fight a disease. For example, the tetanus and diphtheria (Td) vaccine which is recommended for adults every ten years.