Your immune system does a lot of amazing things. Keeping this system strong helps it fight off infections so you can stay healthy.
Although you’re born with all the cells of your immune system, it gets stronger throughout your life as you expose your body to more germs. This is called acquired immunity.
In this article, we take a closer look at what acquired immunity is, why it’s important, and how you can strengthen it.
Acquired immunity is immunity you develop over your lifetime. It can come from:
- a vaccine
- exposure to an infection or disease
- another person’s antibodies (infection-fighting immune cells)
When pathogens (germs) are introduced into your body from a vaccine or a disease, your body learns to target those germs in the future by making new antibodies.
Antibodies from another person can also help your body fight an infection – but this type of immunity is temporary.
Acquired immunity is different than innate immunity, which you’re born with. Your innate immune system doesn’t fight specific germs.
Instead, it protects against all germs, like bacteria and viruses, by trying to keep them from entering your body. Your innate immune system includes things such as:
- your cough reflex
- stomach acid
- your skin and its enzymes
If pathogens get through the barriers in your innate immune system, specific antibodies in the rest of your immune system need to mobilize to fight them off.
Active immunity and passive immunity are the two types of acquired immunity.
Active immunity is the most common type. It develops in response to an infection or vaccination. These methods expose your immune system to a type of germ or pathogen (in vaccinations, just a small amount).
Immune cells called T and B cells recognize there’s an “invader” pathogen and activate the immune system to fight it.
The next time the T and B immune cells encounter that specific germ, they’ll recognize it and immediately activate the rest of your immune system to prevent you from getting sick.
Passive immunity develops after you receive antibodies from someone or somewhere else. This type of immunity is short-lived, because it doesn’t cause your immune system to recognize the pathogen in the future.
There are two main types of passive immunity:
- Maternal antibodies are antibodies that transfer from a mother to child. This usually happens across the placenta or through breast milk, especially in the first few days after birth.
- Immunoglobulin treatments are antibodies that are usually used to treat people at risk for infections, like after a snakebite or a baby born to a mother with hepatitis B. These antibodies are made in a lab, or come from other people or animals.
Both natural and artificial sources of immunity can be active or passive.
- Natural sources aren’t specifically given to you to boost your immunity. Instead, they’re something you acquire by natural means, like an infection or from your mother during birth.
- Artificial sources of immunity are given to you for a specific purpose. They include vaccinations or immunoglobulin treatments.
Your immune system helps keep you healthy by figuring out when something harmful enters your body, and then fighting it so you don’t get sick. The stronger your immune system is, the more likely you are to stay healthy.
A healthy immune system:
- attacks viruses and bacteria that can make you sick
- helps heal wounds
- causes inflammation when it needs to, such as a fever to help get rid of a general infection
- stops long-term inflammation
Acquired immunity makes your immune system stronger. Vaccines, for example, expose your immune system to small amounts of pathogens that won’t make you sick.
Your immune system learns how to recognize those germs, so the next time it encounters them, your immune system will know how to naturally fight them off.
Getting your recommended vaccinations is the best way to boost your acquired immunity.
People need different vaccines depending on their age, where they live, and their job. In general, most adults can boost their immunity with vaccinations against:
- measles, mumps, and rubella (MMR vaccine)
- tetanus, diphtheria, and pertussis (whooping cough) (Tdap vaccine)
Talk to your doctor about what vaccinations you should get.
You can also help boost your immunity by only taking antibiotics for conditions that bacteria — not viruses — cause. For instance, antibiotics won’t help clear up a cold or flu, as a viral infection causes those illnesses.
It’s also important to take the full course of your antibiotics if your doctor prescribes them to help fight off a bacterial infection.
Acquired immunity helps your immune system get stronger. And the stronger your immune system is, the less likely you are to get sick.
When your immune system is exposed to a pathogen, it learns to recognize it. This can make your immune system better equipped to fight off that type of germ the next time you’re exposed to it.
Getting recommended vaccinations is the best way you can help build your acquired immunity and boost your immune system.