Vaccination is a simple, safe, and effective way of protecting people against harmful diseases, before they 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.
Most vaccines are given by an injection, but some are given orally (by mouth) or sprayed into the nose.
Vaccination is a safe and effective way to prevent disease and save lives – now more than ever. Today there are vaccines available to protect against at least 20 diseases, such as diphtheria, tetanus, pertussis, influenza and measles. Together, these vaccines save the lives of up to 3 million people every year.
When we get vaccinated, we aren’t just protecting ourselves, but also those around us. Some people, like those who are seriously ill, are advised not to get certain vaccines – so they depend on the rest of us to get vaccinated and help reduce the spread of disease.
During the COVID-19 pandemic, vaccination continues to be critically important. The pandemic has caused a decline in the number of children receiving routine immunizations, which could lead to an increase in illness and death from preventable diseases. WHO has urged countries to ensure that essential immunization and health services continue, despite the challenges posed by COVID-19.More information about the importance of vaccines is available here.
Vaccines reduce risks of getting a disease by working with your body’s natural defenses to build protection. When you get a vaccine, your immune system responds. It:
• Recognizes the invading germ, such as the virus or bacteria.
• Produces antibodies. Antibodies are proteins produced naturally by the immune system to fight disease.
• Remembers the disease and how to fight it. If you are then exposed to the germ in the future, your immune system can quickly destroy it before you become unwell.
The vaccine is therefore a safe and clever way to produce an immune response in the body, without causing illness.
Our immune systems are designed to remember. Once exposed to one or more doses of a vaccine, we typically remain protected against a disease for years, decades or even a lifetime. This is what makes vaccines so effective. Rather than treating a disease after it occurs, vaccines prevent us in the first instance from getting sick.
Vaccines work by training and preparing the body’s natural defences – the immune system – to recognize and fight off viruses and bacteria. If the body is exposed to those disease-causing pathogens later, it will be ready to destroy them quickly – which prevents illness.
When a person gets vaccinated against a disease, their risk of infection is also reduced – so they’re also far less likely to transmit the disease to others. As more people in a community get vaccinated, fewer people remain vulnerable, and there is less possibility for passing the pathogen on from person to person. Lowering the possibility for a pathogen to circulate in the community protects those who cannot be vaccinated due to other serious health conditions from the disease targeted by the vaccine. This is called “herd immunity.”
“Herd immunity” exists when a high percentage of the population is vaccinated, making it difficult for infectious diseases to spread, because there are not many people who can be infected. But herd immunity only works if most people are vaccinated. At the same time, herd immunity does not protect against all vaccine-preventable diseases. For example, tetanus is caught from bacteria in the environment, not from other people, so those who are unimmunized are not protected from the disease even if most of the rest of the community is vaccinated.
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 vaccines save between 2 and 3 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.