Question: What would the "perfect" zombie virus have to be capable of doing? Would it be possible?

Claire Shooter answered on 17 Jun 2014:

Hi, great question! World War Z is one of my favourite books of all time (shame about the movie)…

I suppose a ‘perfect’ zombie virus would need to be
1. Infectious; transmitted by bites (i.e. saliva > blood)
2. Able to instil an unquenchable desire to bite people
3. Capable of reanimating dead flesh

1. Infection: Should be easy enough – the Hepatitis viruses are blood-borne infections but can be transmitted through saliva. One of these viruses can be the scaffold we add all our zombie genes into.

2. Hunger: Ghrelin is a hormone in your brain which regulates your hunger. Some genetic diseases are associated with a high level of ghrelin in the blood. Sufferers develop an insatiable hunger – they feel like they are starving all the time, and will therefore eat obsessively and can even become violent if people try to stop them. To instil this hunger in our zombies, we would need a gene that upregulated ghrelin in the blood. People with high ghrelin stop short of running after people and biting them, so we need to add some aggression in too: It is hard to know what genes are associated with aggression because a lot of social and psychological factors are usually involved in rage. Some genes that have been tentatively linked to violent behaviour we could add in are: PET-1, MAOAH-L, DAT-1 and DRD-2.

3. If I knew of any genes that caused immortality or reanimation I would probably not be here talking to you right now – I would either be on a superyacht or cackling in an evil lair. The best I can offer on this front would be the following:
a) Cancer associated genes which stop damaged cells from naturally dying. All cells have a finite lifespan and must eventually die. In cancer, cells stop responding to the signals which tell them to die. We would need one of these for the zombies
b) Increased stem cell division. These cells divide to replace old cells which have died. This might stop the body dying so rapidly, even if it becomes damaged.

Unfortunately this is still a far cry from getting a shuffling, groaning zombie. The main problems are that without flowing blood to bring oxygen and remove waste from the body all the cells will die, and without brain stimulation none of the limbs or the jaw will work. You would have to fit all your zombies with pacemakers to keep the blood pumping and some sort of electric graft could potentially be fitted into the brain to stimulate the right sequence of nerves for walking. So, thankfully for everyone, I don’t think a true zombie virus can be made, but you can certainly make people angry and infectious. Therefore, you will have to settle for living zombies, like the ones in 28 days later.

There is some cool zombie science out there: A paper published a few years ago used a mathematical model to work out how fast a zombie infection might spread and how it might be contained. You can read it here! http://mysite.science.uottawa.ca/rsmith43/Zombies.pdf You could also read about the creepy fungus Ophiocordyceps unilateralis that turns ants into zombie slaves here http://www.scientificamerican.com/article/zombie-ant-fungus-parasite/