Saturday 22 October 2011

Contagion And Edexcel Topic 6

Paul and I have just got in from seeing "Contagion" at the cinema. It's a film I'm thinking about taking the A2 class to see, as in Topic 6 of Unit 4 they have to cover infectious diseases. It'd be quite good fun, I think, though I am also thinking about questions I could ask them on a worksheet afterwards. I'm going to throw out some ideas about the film and its relevance to A-Level Biology, so I should warn you now that this post will contain SPOILERS.


The disease is a virus, spread via fomites. I may ask students: Can you name other means of transmitting a pathogen from one organism to another? What advice is given to people to prevent spread of the disease via fomites?

Dr Erin Mears explains the use of the R0, the basic reproduction number. MEV-1 is estimated to have an R0 of 2, which means as Alan points out, after 30 steps that's 1 billion people infected - 230 is 1,073,741,824. After a phylogenetic analysis MEV-1 is found to have an R0 of 4. Assuming a global population of 7 billion, how many days will it take to infect the entire human population? Why are 100% of the population actually unlikely to be infected?

A phylogenetic analysis of the virus is produced. What characters would they have used in order to produce a phylogeny?

The virus infects the lungs and the brain. How does it destroy all the cells in which it is grown? What is responsible for the symptoms shown by the infected people?

Dr Ally Hextall injects herself with a vaccine that is found to be effective in Rhesus macaques. She then exposes herself to the virus. What are the ethical implications of this action? How do clinical trials normally work (refer to AS study on clinical trials)? How could Dr Hextall's actions have jeopardised the research and development of the vaccine?

Dr Ellis Cheever telephones his wife and tells her the virus is serious before advising her to return to Atlanta, despite a policy decision to not inform anyone of the status of the virus. Is this ethical? Are scientists involved in research of this nature obliged to expose their families to equal risk? What would you do in Dr Cheever's situation?

At the end of the movie, vaccines are provided to people via birthdate lottery over the course of a year. Many vaccination programmes restrict themselves to children, the elderly, pregnant women, people with long-term health conditions and their carers. Why was that not an option? Which is fairer?

I'd be really interested to know what you think of this, and whether it can be improved upon. And of course, I'd like to hear from virologists and epidemiologists as to whether there were any glaring errors in the film. My guess is that, given the sheer number of scientific consultants on the film, it's been pretty well tested for accuracy and plausibility. There is a superb website associated with the film: Contagion: Are You Ready?. I think it could easily be used for in-class activities or extension assignments.

And on a less nerdy note, it was a cracking good film.

1 comment:

  1. Excellent film and some great thoughts about what to ask students who have seen the film. I would recommend and AS/A2 Biology student to see the film as it is great and hopefully inspiring and scary in equal measures. I've written my own thoughts on the film here http://wp.me/p1TSgB-11

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