Vaccines are products that protect people against many diseases that can be very dangerous and even deadly. Different than most medicines that treat or cure diseases, vaccines prevent you from getting sick with the disease in the first place.
You will see the terms vaccines, vaccinations, and immunizations used across this site. The following is a simple guide to help you remember their definitions:
- Vaccines are products that produce immunity to a specific disease. When you are immune to a disease, it means you are protected against that disease (you can be exposed to it without becoming sick). Most vaccines are given by injection (needle), but some are given orally (by mouth) or nasally (sprayed into the nose).
- Vaccination is the act of introducing a vaccine into the body to produce immunity to a specific disease.
- Immunization is the process by which a person or animal becomes protected against a disease. This term is often used interchangeably with vaccination.
Vaccination is a simple, safe, and effective way of protecting you against harmful diseases, before you come into contact with them. It uses your body’s natural defenses to build resistance to specific infections and makes your immune system stronger.
Vaccines train your immune system to create antibodies, just as it does when it’s exposed to a disease. However, because vaccines contain only killed or weakened forms of germs like viruses or bacteria, they do not cause the disease or put you at risk of its complications.
Vaccines protect us throughout life and at different ages, from birth to childhood, as teenagers and into old age. In most countries you will be given a vaccination card that tells you what vaccines you or your child have had and when the next vaccines or booster doses are due. It is important to make sure that all these vaccines are up to date.
If we delay vaccination, we are at risk of getting seriously sick. If we wait until we think we may be exposed to a serious illness – like during a disease outbreak – there may not be enough time for the vaccine to work and to receive all the recommended doses.
If you have missed any recommended vaccinations for you or your child, talk to your healthcare worker about catching up.
Without vaccines, we are at risk of serious illness and disability from diseases like measles, meningitis, pneumonia, tetanus and polio. Many of these diseases can be life-threatening. WHO estimates that childhood vaccines alone save over 4 million lives every year.
Although some diseases may have become uncommon, the germs that cause them continue to circulate in some or all parts of the world. In today’s world, infectious diseases can easily cross borders, and infect anyone who is not protected
Two key reasons to get vaccinated are to protect ourselves and to protect those around us. Because not everyone can be vaccinated – including very young babies, those who are seriously ill or have certain allergies – they depend on others being vaccinated to ensure they are also safe from vaccine-preventable diseases.
Vaccines protect against many different diseases, including:
- Cervical cancer
- Ebola virus disease
- Hepatitis B
- Japanese encephalitis
- Yellow fever
Some other vaccines are currently under development or being piloted, including those that protect against Zika virus or malaria, but are not yet widely available globally.
Not all of these vaccinations may be needed in your country. Some may only be given prior to travel, in areas of risk, or to people in high-risk occupations. Talk to your healthcare worker to find out what vaccinations are needed for you and your family.
Nearly everyone can get vaccinated. However, because of some medical conditions, some people should not get certain vaccines, or should wait before getting them. These conditions can include:
- Chronic illnesses or treatments (like chemotherapy) that affect the immune system;
- Severe and life-threatening allergies to vaccine ingredients, which are very rare;
- If you have severe illness and a high fever on the day of vaccination.
These factors often vary for each vaccine. If you’re not sure if you or your child should get a particular vaccine, talk to your health worker. They can help you make an informed choice about vaccination for you or your child.