Countries like Ghana certainly need a vaccine against malaria. Doctors here see 3.5 million cases a year, almost a million of them in young children. Measures like impregnated bed-nets that stop mosquitoes biting and spreading the malaria parasite do already help. But they're far from perfect - children especially don’t like them because you get hot and sticky.
When I visited the rainforest village of Keniajo, I saw the human cost. I sat with local health worker Elvis Boache and mother-of-five Mavis Appiah. We talked through an interpreter but I didn't need any words to see the pain of remembering in Mavis's eyes - remembering her baby son Kelvin who died of malaria.
All the homes we visited had been touched by the disease. Elvis tries to spot malaria early so he can refer families to local clinics. But this is a poor country. Often parents have no transport to take their sick children to hospitals. They have to wait until they can hitch a ride - usually when farmers take their produce to market on Mondays. But waiting with malaria can be fatal.
So a vaccine would be a potent addition to the armoury of health workers like Elvis. (Much to my amazement he already has a smart phone which he can use to access patients' records and add to them). And the new malaria vaccine from GSK looks like it could be that potent weapon.
The early results of its trials in seven African countries show promise. Doctors told me for every 1,000 children they vaccinate they could prevent over 900 cases of malaria. When the final results are in and if it's approved by the European Medicines Agency, GSK say they could make 30 million doses of the vaccine by next year.
When I met Sir Andrew Witty, GSK's chief executive in London, he compares the vaccine to penicillin. That's because it's the first vaccine against a parasite, rather than a bacterium or a virus. And just as the discovery of penicillin lead to a whole spectrum of new antibiotics, the design of the first anti-parasite vaccine has the potential to open up a new field of treatment.
He also firmly scotched any idea that GSK would be making mega bucks from a vaccine that was too expensive for the people who need it most. He told me they were determined to make it cheap enough to be available in poor countries like Ghana.
They would price it on a non-profit basis, recovering only the manufacturing costs (and not the huge development costs) plus five percent, which would be ploughed back into more research on malaria.
That's a policy Sir Witty has pursued since he became chief executive five years ago. Then he said GSK planned to cut its prices in 50 less developed countries to 25 percent of prices in the US and the UK - or less. He said at the time that large global companies should show that they've got "a more balanced view of the world than short-term returns."
If the vaccine is approved and turns out to be affordable it could make a massive difference in places like Keniajo and to mothers like Mavis Appiah.