Prof Wendy Barclay, chair in influenza virology at Imperial College London, said other more complex viruses make proteins at different times during replication, but what is clever is that influenza can do this in such a simple way.

BBC: Flu virus 'knows when to attack'

Each day EDS battles 650 attempted break-ins and three new viruses at the complex of 50, 000 servers it runs for 2, 500 clients and 3 million users.

FORBES: Scare Tactics

Each day it battles 650 attempted break-ins and three new viruses at the complex of 50, 000 servers it runs for 2, 500 clients and 3 million users.

FORBES: Scare Tactics

At the same time, office technology has become more complex and diverse, and the threat of viruses and worms has increased.

WSJ: Best Buy Jumps Into Small Business IT Services

Another method of creating a candidate virus also mixes wild virus with a second, fast-growing strain, but instead of growing them in eggs, lets the viruses mingle in a special solution while scientists manipulate them through a complex technique called reverse genetics.

CNN: Candidate virus for H1N1 vaccine arrives at CDC

Existing vaccines work against viruses and bacteria, but the parasite that causes malaria is a more complex type of organism.

ECONOMIST: Malaria research gets a shot in the arm