Scientists believe they’ve come a step closer to understanding how the body ‘remembers’ to fight illnesses.

Researchers at the Garvan Institute of Medical Research in Sydney, Australia, say they’ve discovered ‘micro-organs’, tiny banks of cells that act as a central point for the body to battle returning infections.

Scientists at the Garvan Institute of Medical Research in Sydney, Australia have discovered the difficult-to-see micro-organs, named SPFs (subcapsular proliferative foci), thanks to 3D imagery

The discovery of the minute cell headquarters, which researchers have dubbed SPFs (subcapsular proliferative foci), could help us to understand how vaccines let the body remember how to tackle an infection it has seen before.

Tests were carried out on mice, which have similar tissue to humans. It’s hoped the breakthrough discovery will now help vaccines of the future be more accurately developed.

The slender, flat ‘micro-organs’ harbour information on the immune system, and can transform into white blood cells to fight infection directly.

The hard-to-spot shape – and the fact they only appear fleetingly when someone falls ill – suggests scientists have long since missed the micro-organs’ presence in the body when using microscopes.

However, developing technology means 3D imagery has put SPFs, which appear on the lymph nodes, in view for the first time.

Scientists say the discovery of ‘micro-organs’ could help vaccines more effective in future

Senior researcher Tri Phan said: ‘Until now we didn’t know how vaccines trained the immune system.

‘When you’re fighting bacteria that can double in number every 20 to 30 minutes, every moment matters.

‘To put it bluntly, if your immune system takes too long to assemble the tools to fight the infection, you die.

‘This is why vaccines are so important. Vaccination trains the immune system so that it can make antibodies very rapidly when an infection reappears.

‘Until now we didn’t know how and where this happened.’