British scientists have begun work on a vaccine against the H1N1 swine flu virus.

Their efforts are under way at the National Institute for Biological Standards and Control (NIBSC) in Hertfordshire.

The NIBSC is one of a small group of influenza centres around the world which will create a seed vaccine strain which could then be grown in bulk by manufacturers.

Its scientists need a steady hand to drill a hole in a hen's egg.

For that is the first step in the creation of a vaccine against the swine flu virus.

Scientists at NIBSC, which is part of the Health Protection Agency, say eggs are ideal for growing up flu viruses.

"They are like virus production factories," its principal scientist Dr John Wood explained.

"Eggs have been used for decades to make flu vaccines. It's an old technology but it works very well."

I was allowed into one of the containment labs which will be used to make the vaccine but not where the live virus is being used.

This is not because of infection but because I might contaminate the vaccine production process.

It involves scientists painstakingly injecting a small amount of virus into each egg which will then be incubated over the weekend.

By Monday, they should have enough virus to begin the next stage.

Two different techniques are being used.

First, "reverse genetics", where scientists take the H and the N surface proteins from the H1N1 virus and mix them with a laboratory virus known as PR8.

This creates a harmless hybrid virus which can be used for the vaccine.

The second technique involves injecting both the H1N1 and PR8 viruses into eggs and allowing the hybrid strain to be created through a natural re-assortment of their genes.

The vaccine will work by tricking the immune system into thinking it has been infected with the H1N1 swine flu virus so that it creates antibodies against it.

http://news.bbc.co.uk/2/hi/health/8029917.stm