Viruses, Part 3 - To Vaccinate or Not Vaccinate? That is the question.
Lesson 7 of 23
Objective: Students will be able to consider the public health benefits of vaccination and decide whether or not the needs of the individual supersede the needs of the population.
Begin with a warm-up question: Do you think a disease transmitted by person-to-person contact would spread faster in an urban or a rural environment? Explain.
I begin with this question because it is a good lead into the activity that follows, in which students will model viral transmission. One of the key points that I hope to hear from students in their responses to the question that viral transmission happens more quickly in densely populated areas.
After discussing the warm-up, tell students to consider the classroom as an environment in which one of us had been exposed to a virus. Ask them high likely is it that others of us would become infected and then pose three questions to students:
- Do you think people always know when they are exposed to a virus?
- If you were infected, how would you go about identifying who infected you?
Explain to students that we are going to model viral transmission today with a short lab I call, “I Love Biology” virus transmission lab. Distribute written instructions and explain the procedure.
- Students randomly select numbered cups or test tubes that contain a clear liquid (water) that is intended to represent their body fluids. However, one of them will be given a cup that contains a few drops of Sodium Hydroxide. This represents the virus and so that student will already be infected with the disease and have the potential to infect those people with whom (s)he swaps bodily fluids. No one knows if they are infected or not.
- Next, students will need to swap bodily fluids with three people in the class.
-Choose a partner
-One student needs to pour his/her liquid into the other person’s cup.
-Now their fluids have mixed.
- Pour half of the liquid back into the empty cup. Both students now have an equal amount of bodily fluids.
-Record the partner’s name on a sheet of paper.
-Students only need to do this THREE times!
Model how to transfer specimen between two individuals and remind students to wear goggles at all times and keep a written record of names. walk around to ensure safe lab practice as students exchange liquid between cups.
Remind students to return to their seats as soon as they have made the 3 exchanges. Set the timer and release the students to begin. I like to play music during a short timed task like this. Music tends to raise the energy of the group and motivate them to move quickly to get the task done. When the 3 minutes ends and the music stops, students should be done and back in their seats.
After the exchange period ends, the teacher plays the role of the doctor. Explain that you will place a few drops of Phenolthaline indicator into students’ cups. If pink, the student tests positive (+) for the virus. If the solution remains clear, the student tests negative (-) for the virus.
After identification of those who have contracted the virus, use a table written on a whiteboard to collect specifics about who shared fluids so that the class can determine who the likely carrier in the room and note how many people were infected with the virus. This lab really is a strong visual demonstration of how virus transmission occurs. Tie this activity back to the original question of the day and ask how the class experience would be different if the class were smaller or larger. Look for student responses that show they understand that transmission occurs faster in more densely populated areas.
Other questions to ask the class include:
- Is it important for us to know who the likely carrier in the class is? Why?
- How can we identify who is the likely carrier in the class?
- Do you think a similar process is followed in the real world as it relates to disease spread and identification of carriers?
- What responsibility do individuals have if they notified that they have been exposed to a virus by contact with a carrier?
- What is one “sticky thought” that you will take from this disease spread simulation?
I like this lab because of its great visual impact. Students become visibly concerned as they wait to see if their liquid turns pink, which indicates they are infected with the "I love Biology" virus. I use this activity as a teachable moment to remind students that they cannot make assumptions about who is or who is not infected with an infection, be it sexual or otherwise. Their best protection against exposure to infections are preventive practices, from regular hand washing to abstaining from risky behaviors.
After completion of the lab, ask students to show by raised hands if they have ever heard of a virus called HPV. Students then participate in a modified philosophical chair activity where they respond to several statements by getting up from their seat and walking to stand at either the “TRUE” sign or “FALSE” sign as I read and project statements about HPV. In preparation for this activity, post two signs on opposite sides of the classroom. Before beginning, ensure that students understand that they are to move quickly to the the sign that reflects their answer to the statement and stand there until the next statement is read.
My main purpose in conducting this activity is because it is a quick and effective way to establish a base of knowledge in the student group on the subject matter before we move into the case study that will follow. Explain to students we will not engage in discussion until the case study because the purpose of this is to raise their awareness of HPV, not to engage in a discussion until they have all the information to make an informed decision.
NOTE: I emphasize that this information is not intended to suggest that they should be vaccinated. It is only intended to raise awareness about the HPV virus, which is the focus of the case study.
Place students into small groups of 3-4 students. I typically assign students to heterogeneous groups. But, because of the nature of the discussion, assign students to gender-based groups in order to facilitate more open and honest dialogue among 9th grade students, who may be less likely to engage in discussion in a mixed gender group. Instruct the groups to designate a reader, time keeper, recorder and reporter before they begin.
Reader- read the narrative aloud to the group.
Time keeper - keep track of the time allotted and the tasks.
Recorder - write the responses to the questions from the group’s discussion.
Reporter - report out the group’s findings when we come back together as a large group.
Distribute large sheets of paper and markers for the groups to document their responses to the questions. Have them post their responses on the walls around the room once complete.
Allow the groups to carousel (walk around the room) and view the other groups' responses to the questions. This activity allows them to compare and contrast their responses with their peers.
Inform students that this assignment will be a peer-graded assignment and share a peer evaluation form that they will use to rate themselves and one another.
Taking the last question from the peer evaluation form, ask students, “What did you learn about working in a group from this project that you will carry into your next group experience?” Engage students in an open discussion because it allows them to hear their peers reflect about the process and it hopefully will elevate the group experience the next time students work in groups. Hearing the comments of peers allows those who did not pull their weight hear how their choices may have affected the group and hopefully will contribute more next time. Those who struggle relinquishing control might learn something from those students who did not fully engage in the process if they share what they learned, as well.