Unit 2

SARS-CoV-2 origins and how humans are infected

This is a new curriculum. We are refining the materials and teaching support according to teacher feedback. If you have any questions or comments, please use the contact form on the Get Help page and we will respond promptly. Thanks for your patience and understanding!

Lesson 2.1

How did SARS-CoV-2 infect humans?

This lesson explores how the COVID-19 pandemic originated when the SARS-CoV-2 virus first infected humans.


Lesson Objectives

By the end of the lesson, you will be able to…

  • Define a reservoir and intermediate host in viral infections.
  • Explain how the amino acid sequence of coronavirus spike proteins can be used to track virus transmission between animals.
  • Infer how SARS-CoV-2 was transmitted across animal species based on the amino acid sequence of the spike protein in different viral strains.

2.11-2.12 How are infections transmitted? Animal to human transmission: Zoonosis (7 slides)

How do humans become infected with a pathogen like SARS-CoV-2? You’re going to start with a quick review of the ways different pathogens are transmitted and then zoom into transmission from animals, or zoonosis. You’ll learn about how the horseshoe bat is critical to coronavirus infections.


2.13 How did coronaviruses come to infect humans? (17 slides)

This section takes a closer look at the animal reservoirs for coronaviruses and you’ll explore the current puzzle about where exactly SARS-CoV-2 came from. Why do we even care? You’ll find out!


2.14 How does SARS-CoV-2 infect humans? The Spike protein (13 slides)

Before you can use Spike protein mutations to track SARS-CoV-2 on its journey across species, you need to know which parts of the Spike protein will give you the best information. This section focuses on where you will be looking.


2.15 Tracking zoonosis across the species barrier (25 slides)

Now, you’ll do an activity to try to figure out where SARS-CoV-2 went after bats – into civets, pangolins or both! This data was taken from very new studies and you will be the first to do this exercise.


2.16 Where do pangolins fit in? (26 slides)

Finding pangolins infected with SARS-CoV-2 has led to intense speculation that they could be the intermediary host. You’ll apply your new skills at mutation analysis to deduce whether that’s possible.


2.17 Vocab review


2.18 Apply your new knowledge!
Read the following news article about the search for an intermediate host for SARS-CoV-2 and answer the questions on your worksheet. You can find the link here.


Documents:

2.18 Reading worksheet

Lesson 2.2

Lesson 2.3

Lesson 2.4