HIV and AIDS
n today's world it is important to understand the way the HIV virus leads to AIDS and how the virus is transmitted from person to person. This activity begins with a simple explanation of HIV and AIDS. The way that HIV infection reduces the number of antibodies is revealed using some short videos and a structured worksheet. There is also a video showing more detail of the transmission of HIV, and a discussion on the impacts of HIV and AIDS in society.Lesson Description
Guiding Questions
What does HIV do to the body? How does it lead to AIDS? Why is AIDS called a syndrome?
Activity 1 Introduction to HIV & AIDS
Watch this short animation 
HIV & AIDS explained in a simple way
Watch this second video which shows the way T-lymphocytes work in the immune system. HIV and T-lymphocytes.
How does the HIV damage to T-cells affect the number of B-lymphocytes which make antibodies?
Complete this 
Summary worksheet on HIV to help record structured notes to answer this question.
For a summary of the effects of HIV infection on antibody production, which may help students to complete the worksheet, simply click the eye icon.
A Summary of the effect of HIV infection and the development of AIDS
HIV is a virus which Infects helper T-cells (white blood cells)
With infection the HIV replicates using the metabolism of the helper T-cell
This replications kills the helper T-cells and their number declines.
The immune system response to infections is slower than it was before.
B-lymphocytes are not activated so quickly.
B-lymphocytes do not make as many antibodies
Opportunistic infections can more easily grow in the body.
AIDS is defined by:
- HIV infection and a very low helper T cell count, or
- HIV infection with opportunistic infections is called AIDS
Activity 2: Further details about methods of transmission of HIV
The different methods of transmission of HIV each carry their own risk. The extent to which individuals in different societies can minimise or eliminate each of these risks could be considered.This animation Transmission and Prevention of HIV describes the common and less common ways in which HIV can be transmitted from one person to another.
Warning: the video covers some information about sexual intercourse and homosexuality.
Activity 3 - The social implications of AIDS - discussion
- Students are each given two or three sticky notes each.
- Students are asked to write something they know about the implications of HIV or AIDS in society.
- The sticky notes are collected and re-distributed at random (so that individuals don't get embarrassed)
- The class is split into two equal sized groups
- The groups are asked to organise their post-it notes onto the scale; Strongly Agree, Agree, Unsure, Disagree strongly disagree.
- For each statement the group needs to have a justification why they agree or disagree. Where students are unsure they should agree on a question which will help to find out missing knowledge.
Consideration could be given to some of the following points;
- the severe problems in sub-saharan Africa.
- the different ways HIV can be transmitted.
- the cost of treatment.
- the stigma attached to being HIV positive.
- the affects of HIV infection on friends and family.
- views held by different types of people.
- the moral obligation of those with the technology & wealth to help other poorer societies.
Teachers notes
The first activity uses two videos to introduce HIV and AIDS. Each video is only 3 or 4 minutes long and students could watch them twice if necessary.
There is a worksheet on which students answer questions about the information in the two videos.
Model answers are available here: HIV and AIDS model answers and access to them can be filtered by teachers in the Student Access section.
Activity 2 is beyond the IB syllabus but valuable information for young people. Personally I would include this in my lesson. The information in the film is factual and not judgemental and if would help to set the scene for Activity 3.
Activity 3 is a debate, based on an activity on the AVERT website. It provides a clear structure to explore student opinions and ideas about HIV and AIDS in a way which allows students to ask questions without fear of embarrassment.
Ground rules for this type of lesson are worth mentioning to students. These can be simple such as:
- Care about others.
- Don't ask personal questions.
- Don't answer a question if you don't feel happy about it. (say, "I don't think that is a good question")
- Remember that discussion which happen during this lesson may not be appropriate outside of the class.
There is a great animation which links transcription and translation to the HIV life cycle on DNAtube here: Animation of HIV lifecycle it was considered too complex for SL Biology.
Extension idea
In the future it is likely that COVID-19 will become a better illustration of virus pathogens than HIV. This short video from VOX Why so mant Covid-19 Variants of concern? describes the gradual evolution of the COVID-19 virus into variants. It could make an interesting extension, or a link to Evolution examples page of the Evolution topic.