The European Union on Thursday came up with another $31 million to fight Ebola, as the bloc's leaders pressed to create a $1.26 billion fund to fight the deadly virus.

British Prime Minister David Cameron set that target last week and prior to Thursday's start of a two-day EU leaders' summit, the bloc's total anti-Ebola commitments were over halfway to that goal. Britain says it has committed$200 million toward fighting Ebola, more than any other EU nation.

"We need other European countries to do more," said Cameron as he entered EU headquarters.

EU Commission President Jose Manuel Barroso said the money promised Thursday would go for medical research on an Ebola vaccine.

"We are in a race against time on Ebola," Barroso said. "We must address both the emergency situation and at the same time have a sustained medium and long-term response."

An international consortium led by the Institute of Tropical Medicine in Antwerp, meanwhile, announced it would study whether treating Ebola patients with antibodies from the blood of survivors could help. Researchers got $3.7 million to test the safety and effectiveness of treating patients with blood and plasma from people who have recovered from Ebola.

In Geneva, the World Health Organization said the Ebola outbreak in West Africa, which has killed more than 4,800 people, remains an international health emergency.

WHO experts said international travelers from the three hardest-hit nations — Guinea, Sierra Leone and Liberia — should still be screened for possible Ebola symptoms to prevent the disease from spreading further. But the experts said there should be no general ban on travel and trade with those countries.

In Spain, five of the 15 people who came into contact with a nursing assistant who survived Ebola were released from the hospital Thursday after spending 21 days under observation and showing no signs of the disease.

The nursing assistant, 44-year-old Teresa Romero, was cleared of the virus on Tuesday.

In Germany, military volunteers practiced climbing into medical protective suits and getting sprayed with bleach in preparation for a mission to support efforts to fight Ebola by the German Red Cross in Liberia.