Understanding how vaccines work first means understanding how your body naturally defends itself against illness. You see, there are germs with bacteria and viruses all around us. Some are relatively harmless, others not so much. A broad term for the kinds of organisms that can infect your body and cause disease is a pathogen. A pathogen can cause illness because the virus, bacteria or microbes that have entered your body have begun to attack and multiply.



Fighting infections with white blood cells

Your immune system employs several tools to fight off these types of infections. The primary defender is your white blood cells, which consist of macrophages, B-lymphocytes and T-lymphocytes. Together these white blood cells attack other cells in your body that have already been infected to eliminate them from your system.

● Macrophages will essentially eat germs and dying or dead cells. Plus, they will also leave behind parts of the invading germs known as antigens – this stimulates the creation of antibodies

● B-lymphocytes are white blood cells that produce antibodies that attack the antigens left behind macrophages

● T-lymphocytes are an additional type of white blood cell that will attack infected cells in your body

When an infection is over, your immune system will have learned how to fight it. In fact, your system even keeps a few T-lymphocytes (sometimes called memory cells) around so that they can go into defensive action quickly if your body is infected by the same type of pathogen again. Also, your B-lymphocytes white blood cells will remember the same type of antigen and quickly produce antibodies against them.

Mimicking your bodies natural infection fighting response with vaccines

Vaccines are generally made up of inactive or weak parts of a germ’s antigens that can trigger the immune response within your body. They can also be made up of something like a blueprint or a fake antigen rather than the real antigen itself, which will also trigger your body’s immune response. Either way, vaccines will stimulate your white blood cells’ fighting response so that your body can defend itself against a certain type of infection.

Depending on how the vaccine is developed, you may need multiple doses to create long-lasting antibodies and memory cells in your system so that your body remembers how to fight the infection quickly if exposed in the future. This process allows you to safely develop immunity to certain types of dangerous and deadly diseases that your body has never encountered before.

What happens after you have a vaccine?

Sometimes, depending on the vaccine and your body, you may experience minor symptoms. This is a totally normal occurrence as the vaccine helps your body build immunity by imitating a real infection. During the fake infection, your body will go through the same process that it would when fighting off a true disease – producing T-lymphocytes and B-lymphocytes that will know how to fight off any similar future infections. But it’s important to remember that you still need to be careful for some time after you first get a vaccine as it takes time for it to come into effect within your body and provide the necessary protection.

What is herd immunity and why is it important?

When many people can be vaccinated it makes it very hard for a pathogen to continue circulating as most of the people it encounters are immune. However, some people aren’t able to be vaccinated because of underlying health conditions. When those people live among large communities of people who have already been vaccinated, it reduces their risk of being exposed to the harmful pathogen as it is unable to spread. This is called herd immunity. That’s why being vaccinated if you can is important – because it doesn’t just protect yourself, it can also protect those around you.