BBC News with Marion Marshall.

Researchers developing a vaccine against malaria have published results showing a high success rates so far. The scientists at an American biotech company irradiated mosquitoes to weaken the malaria causing parasites they carry. The enfeebled parasites were then injected into humans to trigger an immune response. Naomi Grimley reports. “Scientists have known for a while that if a human is bitten by malaria carrying mosquitoes which have been weakened by radiation. That person might build up immunity, but it might take as many as a thousand bites to make that happen. Now an American biotech company in Maryland has built on that knowledge. Researchers irradiated mosquitoes extracted the malaria causing parasites and injected them into volunteers, 12 out of the 15 who'd been given the highest dose, then developed immunity.”

The electoral commission in Zimbabwe has, for the first time, admitted that substantial numbers of voters were turned away from polling stations in last week's elections. It said that more than 300,000 people were prevented from voting and further 200,000 might be influenced in their choice of candidate. But the commission said the mistakes were not enough to prevent victory for President Robert Mugabe. A leading member of the opposition MDC, Tendai Biti, told the BBC that Zimbabweans feltl deeply dejected because so many of them have made extraordinary efforts to vote only to be cheated. “People enlisted en route in just casting their votes, nearly on thousands came from the X people X that things in order to the exist the right to vote. So when they've been taken away from the election like this, there is a problem.”