Immune System


Immune System introduces students to the system in the body that protects us against sickness and disease. Students will learn all about the different components that make up the immune system and be able to explain how they work together to fight illness.

The “Options for Lesson” section on the classroom procedure page lists several suggestions for additional activities. One idea is to send a letter home to parents that asks if their child has allergies. With permission, those students that do could discuss the precautions they have to take as a result.

Buy Now For $1.95


What our Immune System lesson plan includes

Lesson Objectives and Overview: Immune System teaches students about the functions of different parts of this body system. Students will learn how they work together to defend and protect the body against disease. They will also discover how to keep the immune system healthy and working well. This lesson is for students in 5th grade and 6th grade.

Classroom Procedure

Every lesson plan provides you with a classroom procedure page that outlines a step-by-step guide to follow. You do not have to follow the guide exactly. The guide helps you organize the lesson and details when to hand out worksheets. It also lists information in the yellow box that you might find useful. You will find the lesson objectives, state standards, and number of class sessions the lesson should take to complete in this area. In addition, it describes the supplies you will need as well as what and how you need to prepare beforehand. For this lesson, you will need scratch paper and writing paper for the activity, as well as the worksheet handouts.

Options for Lesson

In the “Options for Lesson” section, you will find several suggestions for additional activities and tasks or alternate ways to approach aspects of the lesson. A few of them relate to the activity specifically. Students will work in pairs for the activity, but you could have them work alone or in small groups instead if you wish. You could have them use construction paper or similar supplies to display their stories. While the task does not require drawings, you could choose to require them if you prefer. You may also want to have students complete the practice worksheet before they do the activity. Another option is to send a letter home to parents that asks if their children have allergies. With permission, you could have those students talk about the precautions they have to take as a result of their allergies. Another idea is to assign each student a part of the immune system to research and present to the class. One more idea is to invite a doctor or other medical professional to speak to the class about the topic.

Teacher Notes

The teacher notes page provides one more paragraph of information or guidance about the lesson plan. It notes that students may already have some understanding of the human body and its organs and systems before this lesson. You can use the blank lines on this page to write out any other thoughts you have as you prepare.


The Immune System

The Immune System lesson plan has three pages of content. Students will learn how the human body takes care of itself. People don’t have to do very much or know very much for the body to function as it should. When it comes to sickness and disease, the immune system is at work constantly to fight off bad germs. This system is responsible for keeping the body safe from invading germs that try to attack it every day. It involves several different organs and other components. It works together with the circulatory system, which controls the flow of blood throughout the body.

The lesson explains how there are things in the air everywhere we go that try to attack our bodies. The immune system defends the body against attacks from germs and bacteria in the air, from other people, or in the food we eat. It is comprised of tons of cells, just like any other part of the body. Basically, the immune system works like a fort that protects the body, and it will increase its defenses when necessary.

The system’s components include the skin, white blood cells, and the lymph system. Each component has different functions and responsibilities. They all work together to keep the system running smoothly and properly to ensure the body stays healthy and safe. The lesson describes each one in more detail.

System of Defense

The first component students will learn more about is the skin. The skin is the body’s first defense against germs, or antigens, that try to get in. It covers the body like a guard against harmful bacteria. However, we do have to keep it clean. This is because it’s the first place where bad germs will try to attack. After all, germs spread very easily through skin contact. Hand washing is one of the best ways to help prevent the spread of germs and bacteria.

White blood cells make up another important component of the immune system. They are essentially “watchers of the blood” and multiply constantly because they only live for a few weeks. There are three types of white blood cells: lymphocytes, neutrophils, and macrophages. Neutrophils move in the blood and seek out germs and bacteria that do not belong there. Macrophages are the biggest, and they live throughout the body to help keep it clean during the healing process.

Lymphocytes and the Lymph system

Lymphocytes are the white blood cells that attack infections. There are two types of infections: viral and bacterial. There are also two types of lymphocytes: T-cells and B-cells. T-cells find hidden germs or unhealthy cells and destroy them. B-cells, on the other hand, produce antibodies (proteins that fight germs), which fight specific germs. A B-cell attaches itself to the germ, and then other white blood cells in the body know to destroy that germ.

Students will discover that there are also cells called helper T-cells that tell B-cells to start creating antibodies. These helpers also instruct killer T-cells to attack infected cells. Then memory cells remember the germs that attacked the body. When those same germs come back again, these cells are ready to fight them off.

The lymph system is the final component of the immune system. It includes the lymphocytes that travel throughout the body. Lymph fluid travels to different body parts and picks up bacteria and viruses. It carries the germs to the lymph nodes, which are glands that collect and destroy the germs before they can travel to the rest of the body.

Vaccines, Allergies, and Autoimmune Diseases

The lesson explains to students (or reminds them) that not all germs are bad. Some actually help strengthen the immune system rather than attack it. This is why the body contains cells that remember bad germs and fight them whenever they come back to cause problems again. In fact, it is a good idea to expose the body to some germs because the immune system can learn about them and fight them off. This is how a vaccine works.

A vaccine is basically a weak virus that a doctor injects into the body. The immune system can then work to fight against the virus and remember what the germs were for future attacks. The virus is weak because it has been changed so that it doesn’t actually make a person sick. If the real disease or virus tries to attack, the antibodies that the B-cells produced to fight the germs from the weak virus will know to fight the real virus.

When certain germs attack the immune system too often, allergies often result. The system falsely believes the safe food product or other item is a bacteria or virus. It attacks the substance and ends up causing symptoms like sneezing, itching, sore throat, stomach cramps, hives, runny nose, or other reactions.

Sometimes, this system of defense attacks healthy cells as well. When this happens, it usually means a person has an autoimmune disease, which means the body thinks its own cells are unhealthy. If someone has this type of disease, they often have to take medication to help with a variety of problems that the disease can cause.

Protecting the Immune System

The last part of the lesson plan explains ways to help keep the immune system strong. Some people naturally have stronger immune systems than others. However, keeping this defense system healthy and strong is important for everyone, regardless of how strong it already is.

One way to do this is to reduce stress and get enough sleep. The immune system begins to break down if the body doesn’t get enough sleep. In addition, worrying and stressing about things often slows it down. Other ways to help, which are helpful for the body in general and not just for this body system, include exercise, eating right, and washing our hands.

Students will learn that there are a few ways to tell that their immune system is working correctly. For instance, if they get sick and start to feel better, they know their defense system is working. They can also see it at work as cuts or scrapes begin to heal or when they don’t get the same illness over and over. Even when they get swollen glands or soreness around a cut, this actually means that the body is doing a good job healing.


The Immune System lesson plan includes three worksheets: an activity worksheet, a practice worksheet, and a homework assignment. Each one will help solidify students’ grasp of the material and reinforce what they know. The guidelines on the classroom procedure page explain when to hand out each one to the class.


For the activity, students will work with a partner and pretend they are germs or bacteria trying to invade a human body. They could also be a cell from the immune system. They will write an imaginary story that describes their experience as they try to enter the body from the exterior to the interior. In addition, they must tell the story from the perspective of the germ or cell (first person).

Students can be humorous, serious, or both! The goal is to be creative with explaining how the immune system works from the perspective of a germ or cell. If they want, they can include drawings or sketches. They will need to include vocabulary from the list of terms at the bottom of the first activity page. They can use scratch paper to write a rough draft before completing the final draft.


The practice worksheet has two sections. The first section lists 18 statements and 18 words in a word bank. Students must match the descriptions to the correct term. For the section section, they must describe how a vaccine works using their own words.


The homework assignment requires students to read a paragraph about the immune system. Using the 25 words in the word bank, students must fill in the blanks throughout the paragraph with the correct terms.

Worksheet Answer Keys

The last two pages of the document are answer keys for the practice and homework worksheets. The correct answers are all in red to make it easy for you to compare the pages to students’ responses. The only answer that should have any variation is the second part of the practice worksheet. If you choose to administer the lesson pages to your students via PDF, you will need to save a new file that omits these pages. Otherwise, you can simply print out the applicable pages and keep these as reference for yourself when grading assignments.

Additional information


5th Grade, 6th Grade



State Educational Standards


Lessons are aligned to meet the education objectives and goals of most states. For more information on your state objectives, contact your local Board of Education or Department of Education in your state.

Customer Reviews
5.0 Based on 10 Reviews
5 ★
4 ★
3 ★
2 ★
1 ★
Write a Review

Thank you for submitting a review!

Your input is very much appreciated. Share it with your friends so they can enjoy it too!

Filter Reviews:
Thailand Thailand

Overall experience using this site is excellent!

United States United States

The Immune System

Excellent and easy to follow. My class loved it.

Ilze A.

Immune system

Very informative and great to use in my lesson. Thank you.

Sandra B.

What a gem!

I am so grateful that I found this resource. In addition to the content, I appreciate the visuals.

Leslie P.

Great resource

Fantastic resource. Highly recommended.