Bill Gates warned Wednesday that malaria was back on the rise again and would continue to claim more lives worldwide unless governments reinvigorated their push to eradicate the disease.
Malaria death rates have been in steady decline since 2000 but rose in 2016 as progress towards eliminating the mosquito-borne preventable disease stalled.
Microsoft co-founder turned philanthropist Gates said innovation would be crucial to maintain progress in tackling the disease ahead of its ability to develop resistance to drugs and insecticides.
"This setback where the 2016 cases went up is a real signal to us," Gates, the second richest person in the world, told the 2018 London Malaria Summit, where experts gathered to plot the way forward.
"The funding has to be long-term and we've got to get smarter."
Donors at the summit pledged £2.7 billion (US$3.8 billion), with Gates putting in $1 billion from his foundation. The funding will go into research, data tools and malaria interventions.
Child dies every two minutes
More than 445,000 people died from malaria in 2016, mostly children under five and pregnant women while one child dies every two minutes from the disease. There were 216 million cases in 2016 -- 90 per cent of which were in Africa, according to World Health Organisation (WHO) figures.
Malaria is estimated to cost the African economy more than $12 billion per year and can consume up to 40 percent of a country's healthcare spending.
Deaths from malaria, however, dropped by more than 60 per cent between 2000 and 2015.
Gates said that around seven million lives had been saved and several countries had been declared malaria-free.
"Progress against malaria has been one of the most impressive successes in global health in this generation," the U.S. philanthropist said.
However, he warned: "If we don't keep innovating, we will go backwards. If we don't maintain the commitments, malaria would go back up and kill over a million children a year, because the drugs and the insecticides always are evaded by the mosquitos and parasites."
Attendees at another health conference this week in Dakar heard how African countries suffering from famine or conflict have seen a spike in malaria infections and deaths.
Experts also warned that blood transfusions are a risk factor for malaria, with a study in Nigeria finding that nearly a quarter of the blood stocks in some sub-Saharan countries contain malaria parasites.
WHO's 'fresh fight' call
The London gathering is taking place on the fringes of the biennial Commonwealth summit. Ninety percent of people in the Commonwealth live in countries with malaria.
Summit host Britain has called on the 53 Commonwealth nations to commit to halving malaria throughout member states by 2023.
Such action would prevent 350 million cases and save 650,000 lives, it was claimed.
"It is an ambitious goal, but one that is firmly within our reach," said British Prime Minister Theresa May.
Prince Charles, heir to the thrones of 16 Commonwealth nations, said combating malaria was an issue of "truly global urgency".
While Wednesday's pledges would "prevent much suffering, illness and death", he said, "it is tragically evident that much still remains to be done".
Linking the fight to deforestation, he added that without ending the "utter madness" of "testing the planet's ecosystems to destruction... I fear that we will go fatally compromised into a battle that we cannot afford to lose."
World Health Organization Director-General Tedros Adhanom Ghebreyesus -- who has suffered from malaria and lost a brother to it -- said a "fresh fight" was needed to hold the gains made in fighting the disease.
"We are now at a crossroads. If we relax our efforts, we know that malaria will come roaring back with a vengeance," the Ethiopian diplomat said.
