An experimental drug is being harvested in Kent which could eventually save millions of lives, researchers say.
Researchers hope each plant will provide 20 doses of the protein
Genetically-modified tobacco plants grown at East Malling Research are designed to provide a cheap and effective treatment for HIV and Aids.
After harvesting, the aim is to turn extracts from the plant into a medicinal cream.
Project leader Professor Julian Ma hopes it will be a breakthrough in the treatment of HIV/Aids sweeping Africa.
He said: "There are some huge cost advantages. I think the key is the scalability.
"The second thing is that people in developing countries can't afford to pay, so you have to produce at the lowest cost possible."
The tobacco plants are being grown under strictly controlled conditions at the research site located close to Maidstone.
Researchers at St George's Hospital, in London, are genetically modifying the plants with a bacteria that reacts with them at a genetic level so that they produce a protein called cyanovirin.
Tests on monkeys have shown it to be more than 80% effective at blocking the HIV virus.
Each seed head has around 300 seeds and researchers hope the full grown plant will produce enough protein for up to 20 doses.
The project is now in its third year although it could take up to 10 years before the drug is on the market.