This activity is part of The Truth About Germs unit.

• Use the class body map from the Bad Germs: Keep Out! activity to remind students of the key parts of the immune system and how they protect our bodies.
• Prepare students to watch a video that demonstrates what happens to the body when germs get into our bodies.
• Ask students to listen for answers to the following questions and to be ready to share after the video:
• How do the different parts of the immune system work together?
• What similarities and differences do you see between the video and our body map?
• Use “The Cells that are Part of the Immune System” table on The Story Behind the Scenes page of Arizona State University’s digital comic book, Viral Attack, to preview some of the key immune system vocabulary from the video, which differs from the terms used in the Bad Germs: Keep Out! activity. Emphasize that the specific terms and parts of the immune system are less important than the idea of the different parts working together.
• Show the Viral Attack video (3:41). Consider stopping and pausing at key moments to point out the new parts of the immune system or eliciting students’ initial ideas about how the different parts work together.
• Lead a debrief discussion for students to share their ideas about how the different parts of the immune system work together and how it relates to the class body map.
• Key ideas may include:
• The first wave of defense (macrophages and neutrophils) calls for backup from the T-cells (some T-cells are actually called “killer cells”) when they aren’t able to kill all of the viruses.
• The T-cells call for backup from the B-cells when they aren’t able to kill all of the cells that have viruses in them.
• The B-cells create a “memory” of the viruses so that any B-cell can recognize the virus in the future.
• T-cells and B-cells were documented on the class body map, but connections were not made about how they work together.
• Share that these waves of immune response as shown in the video accurately show how our bodies actually work as a system to protect us from germs.

2. Lead a class discussion to prompt students to consider how our immune systems can be weakened by a variety of factors.

• Transition to the main idea for this activity: Our immune systems don’t always function as well as they should, especially if there are factors that weaken different parts of people’s immune system (such as infections, poor diet, lack of exercise, stress, exposure to harsh chemicals, smoking, drinking alcohol).
• Use the class Question Quadrant to remind students of the unit driving question:  Why do germs make us sick more often during the winter?
• Remind students about what they learned during the Germs All around Us activity about environmental factors that help viruses survive in the winter and the ideas in the Spreading Germs activity about how people interact inside more often during the winter.
• Explain that students will now investigate what may happen to our immune systems during winter to increase the chances of getting sick. Elicit student’s initial ideas about this by asking: Why don’t our immune systems always protect us?
• Lead a discussion to document and follow students’ ideas and thinking.
• Build on their responses to remind them of the tips to support the immune system that they read about in the Attack of the Germs! article during the Bad Germs: Keep Out! activity:
• Eating healthy foods, exercising, getting enough sleep, keeping stress levels low
• Add on to explain that vitamin D from sunlight is another evidence-based factor that helps our immune systems function.

3. Guide students as they read about and analyze data representations that show how our immune systems are impacted by activities differently during the winter versus the summer.

• Explain that students will now become experts on one of these activities and how they impact our immune systems. Organize students into groups of four and distribute the Helping and Hurting Our Immune Systems handout.
• Within their groups, have students determine which activity they will focus on. Direct them to circle the activity and make a prediction about how it might differ between summer and winter on the top section of their handout.
• Then re-organize students into expert groups based on the activity on which they are focusing; for example, all students who are focused on sleep. Distribute the relevant Helping and Hurting Our Immune Systems Data Sheets for the activity they are focusing on.
• Using the relevant page for their activity, prompt expert groups to collaborate in reading about their activity and analyzing a graph showing how people’s engagement in the activity changes seasonally. Students should individually record their findings in the relevant section of their Results Table on the handout, since they will be responsible for reporting to their original group.
• Circulate as expert groups collaborate, using the data sheets as a reference and pressing their thinking in terms of cause-and-effect relationships and how their results help us understand why germs make us sick more often in the winter.
• Students’ ideas for the cause-and-effect pathways should come from the paragraph that they read. For example: For the activity “Eating lots of fruit and vegetables,” one effect is “helping the body create better white blood cells by providing essential nutrients and minerals,” which in turn has the effect of “white blood cells create antibodies and fight germs.” Another effect of eating lots of fruit and vegetables is that it “gives your body fiber feeding ‘good’ microbes in our stomachs,” which has the effect of “help[ing] support digestion and fight infection in your gut.”
• Support data literacy for interpreting the graphs by:
• Reminding students of the steps they have taken in previous activities, such as first identifying what each axis tells us, then what the line means over time.
• Modeling how to interpret one of the graphs.
• After expert groups complete the table for their activity, have them reorganize into their original groups and facilitate as students share with their group members. Prompt students to record results on their finding table.
• Lead a class discussion to review their results and lead to the idea that our immune systems do not function as effectively in the winter, due to decreased eating of fruits and vegetables, exercise, and exposure to sunlight (which means less natural vitamin D).
• Note that the data on sleep shows that people tend to get more sleep during the winter. Getting full hours of sleep is generally considered healthy to allow our body to recover and stay healthy. So we could think that sleeping more during the winter would automatically strengthen our immune system, although this is not often true. Help students make sense of the fact that even though one factor may be helpful to our immune systems during the winter, the other three activities likely outweigh it.
• Be sensitive to the fact that these activities not only vary seasonally, but also between and within communities, especially in regards to race and socioeconomic status (or religion), which may vary among students within your classroom. Emphasize that access to healthy foods and opportunities to exercise are not available to all people and communities in the same ways.

4. Guide question writing for the Germology Game Show to connect learning about the immune system to the unit driving question.

• Lead the class through thematically organizing the four activities as they relate to each quadrant of the class Question Quadrant chart: Germs, People, Environment, or Something Else.
• Prompt students to consider if the new evidence supports or counters their revised hypotheses about why germs make us sick more often in the winter.
• Students may respond: I originally thought that germs make us sick more in the winter because our bodies use more energy to stay warm and can’t fight off germs. I know now that this is only part of the story; our bodies’ immune systems are affected by factors like decreased vitamin D due to lack of sunlight that makes it harder for our bodies to fight off germs.
• Organize students into their original jigsaw groups from Step 3. Guide students to select one or two ideas from this activity to focus on for writing trivia questions and evidence-based answers. Use the section for this activity on the Trivia Question Builder handout to structure their process.
• For this activity, evidence can come from the video about how the different parts of the immune system work together, cause-and-effect pathways about different activities’ effects on our immune systems, and the findings and/or data representations about how those activities differ between the summer and winter seasons.
• Circulate to support and press students’ thinking as they work on their questions and evidence-based answers.