Add to collection
  • + Create new collection
  • We all get sick from time to time. Wintertime, in particular, brings with it colds and flus.

    Rights: Image licensed through

    Sick child

    We all get sick from time to time and don’t feel too good. At this time, our bodies are busy working to make us well.

    Symptoms may include feeling hot and cold, a runny nose, streaming eyes, headaches, tiredness, loss of appetite, then after a few days (or sometimes longer), we start to feel better and are back to normal. So what is happening? Why do we feel so terrible? How do we get better? What is going on inside our bodies?

    Let’s investigate…

    Infection is the invasion of pathogenic (disease-causing) microorganisms in the body and the body’s response to that.

    Pathogenic microorganisms, commonly called germs or bugs, are all around us. They can be easily transmitted from one person to another. Once they get past your skin (part of your first line of defence), they get into your body, your bloodstream and your cells. At this point, your immune system (your second line of defence) kicks in and fights back to destroy the pathogens causing infection.

    Rights: Science Photo Library

    Killer T cells

    Immune cells known as killer T cells help to fight infection in our bodies.

    The immune system

    The immune system

    This interactive explains the different cells, microorganisms and molecules involved in the human immune system.

    The immune system consists of cells, tissues and organs that work together to protect you. We explore the immune system and how it responds to various microorganisms.

    The immune system in action

    This interactive is a simple version of the human immune response to two different pathogens.

    In the article The body’s second line of defence, we look at microorganisms, including some of the pathogens that cause sickness.

    Hand washing and hygiene practices are vital to stopping the spread of infection. In the 1880s, Florence Nightingale was well aware of the importance of hand washing even though microorganisms were not fully understood at that time.

    Every nurse ought to be careful to wash her hands very frequently during the day. If her face, too, so much the better.”

    Florence Nightingale

    We find out what happens when your immune system doesn’t work through the story of David Vetter who lived in a sterile bubble all his life.

    We also take a look at vaccination. This is a way of preventing some diseases by using your immune system to protect you. Vaccination became a global focus with the COVID-19 pandemic. We look at the history of vaccination, as well as current immunisation in New Zealand. This is supported by activities including an investigation into some of the ethical issues surrounding vaccination.

    Māori perspectives

    We explore rongoā – the Māori term for medicines that are produced from native plants in New Zealand. Many of these plants were and are still used to fight infection. Find out more in the article Rongoā Māori and then follow up with the activity Using rongoā Māori.

    Antimicrobial resistance

    Any use of antibiotics automatically creates resistance. Learn why it is an issue, the history of antibiotics and antimicrobial resistance and what you can do to reduce the risk. The context for learning provides ideas on how to incorporate this wicked problem into authentic cross-curricular learning.

    Use this interactive image map to discover a range of resources about bacteria and antimicrobial resistance.

    Antimicrobial resistance – planning pathways

    Use this interactive to discover a range of resources about microorganisms and antimicrobial resistance. Select a label for more information.

    Go here for further information, including the transcript.

    The Infection Inspection citizen science project is using E. coli to help develop a faster test for antibiotic resistance. They need your observation skills to help identify bacteria that have been impacted by antibiotics. This is an engaging way to introduce science concepts.

    Meet the scientists

    Scientists from the Malaghan Institute of Medical Research in Wellington share their research. The article Hookworm and allergies profiles the work of Professor Graham Le Gros, who is working on a vaccine against asthma and allergies. Dr Joanna Kirman explores infectious diseases, like tuberculosis, and how they affect the immune system. This helps her team find cures for these diseases. Dr Bridget Stocker and Dr Mattie Timmer design drugs and make molecules to improve vaccines.

    Rights: The University of Waikato Te Whare Wānanga o Waikato

    Research being conducted at the Malaghan Institute

    Dr Mattie Timmer and PhD student Anna Win-Mason carry out research at the Malaghan Institute of Medical Research.

    Take up the challenge

    We also have some great activity ideas that cover some of the big ideas in science.

    There are also cross-curricular opportunities: Literacy in immunology and Drama with microbes.

    Curious to see how all of this fits together? Check out the unit plans: Fighting infection – the immune system and Fighting infection – reducing infection.

    Being a scientist is a lot like being a detective – you have to think of cunning ways to solve problems and find the answers.

    Dr Joanna Kirman (Malaghan Institute of Medical Research)

    Question bank

    The Fighting infection – question bank provides a list of questions about the immune system, pathogens, vaccines and places where their answers can be found. The questions support an inquiry approach.

    Key terms

    For explanations of key concepts, see Fighting infection – key terms.


    Use this timeline to see some of the historical aspects of fighting infection, covering early discoveries on germs, vaccination, how are our bodies help us to get better and more.

    Related content

    We have curated content in this Viruses and the immune system collection – it explores viruses and how our immune system fights them. Log in to make this collection part of your private collection. Click on the copy icon, and then you can add additional content and notes and share and collaborate with others.

    Find out about antibiotic resistance in these articles:

    The Science of Medicines – Whakatere Waka is an innovative community project that promotes scientific literacy regarding the use and understanding of medicines. The project has a gaming component – we’ve used several of their ideas in the activity Game design for viruses and vaccines. A second activity Viruses and immunity – interpreting infographics uses fact sheets they’ve created.

      Published 2 November 2010, Updated 20 July 2023 Referencing Hub articles
          Go to full glossary
          Download all