The US keeps millions of chickens in secret farms to make flu vaccines. But their eggs won't work for coronavirus.
Few people know where the chickens are kept - their locations are undisclosed as a matter of national security.
Each day, hundreds of thousands of their eggs are trucked to facilities, where they are protected by guards and multimillion-dollar, government-funded security systems.
But these eggs aren't for breakfast; they're the source of your common flu shot.
For the past 80 years, much of the world has relied on chicken eggs for the production of influenza vaccines.
As the coronavirus pandemic spreads, scientists and governments around the world are racing to develop a vaccine - but eggs won't be the answer, said John Nicholls, a Hong Kong University clinical professor of pathology.
Due to having different receptors and other characteristics, the novel coronavirus isn't able to replicate inside eggs the way flu viruses can.
By Jessie Yeung, CNN, March 29, 2020
