Geneva - While many hens lay eggs that are decorated and eaten during Easter season, others work in the name of global health and help produce hundreds of millions of flu vaccines all year long.
Every year, between 450 million and 500 million eggs are used for immunization shots, said Martin Friede, the chief vaccine researcher at the World Health Organization (WHO) in Geneva.
"More than 90 percent of the world's flu vaccine is being produced with the help of eggs," he recently told dpa in Geneva.
Scientists rely on products that cannot be bought in supermarkets.
The quality they need can only be found in special farms where hens are kept under strictly controlled conditions.