A single drug that fights off flu, ebola, yellow fever and other killer viruses could soon be available, thanks to a British breakthrough.
Described as "an antibiotic for viruses", the multi-purpose medicine would be able to treat and even prevent infection.
Importantly, it would be the first to be effective against many different types of viruses. Unlike antibiotics, which tend to zap a range of different bacteria, existing anti-viral drugs only work against one bug.
Researcher Paul Kellam, of the Wellcome Trust Sanger Institute near Cambridge, said: "This has very real implications. This will prevent influenza viruses, dengue viruses, yellow fever viruses, ebola viruses, amongst others, from getting into cells."
The drug has become a possibility thanks to Professor Kellam's discovery of a gene that makes some people extra susceptible to severe flu.
The hundreds of thousands of Britons with the rogue DNA are four times as likely as normal to develop illness so serious it could put them in hospital or even kill them.
The IFITM3 gene makes a compound that stops the flu virus from invading the body's cells. Those with a faulty gene don't make enough of this protein and the bug finds it easier to take hold.
The key now will be to make a drug that raises levels of the compound in the body.
This could be used to treat or even prevent flu in those with the flawed gene.
It may even be possible to help 'normal' people recover more quickly. Although flu is often thought of as a minor inconvenience, it can be deadly, killing up to 12,000 Britons each year, many of them elderly.
Other options include testing people for the rogue gene.
The 0.3 per cent of Britons who have it could be strongly advised to have the flu jab. And during a flu outbreak, those with the faulty gene could be fast-tracked to more powerful treatment.
Excitingly, the drug should also protect against other viruses that use the same mechanism as flu to invade the body's cells. These include the ebola virus, which ran rampant in Africa last year, as well as dengue fever, a tropical illness which claims up to 25,000 lives a year worldwide, and yellow fever, which kills up to 30,000 globally.
Although the medicine has yet to be formulated, Professor Kellam is confident it will be possible. He told the British Science Festival in Bradford that the "antibiotic for viruses" could be just five to ten years away.
The professor's research helps explain why some people get severely ill with flu while everyone around them is healthy. However, with women as likely as men to carry a flawed IFITM3 gene, it does nothing to back up the existence of "man flu."
Those who fancy a duvet day may also want to take note of some other recent British research. Earlier this year, a study from Imperial College London concluded that the average adult gets flu just once every five years.
Researcher Dr Steven Riley said that people often simply misuse the word "flu."
He said: "People don't mean flu when they say 'flu'.
"What they mean is that they have a bad respiratory illness and there are quite a few of these around."