Malaria is one of the most common (1)____ diseases in the world. So far the only kind of (2)____ implemented by the affected countries has been distributing mosquito nets and basic medicines. (3)____ and doctors have been working on a malaria vaccine for many years. However, although all vaccines produced so far have shown good results on monkeys their (4)____ in tests on humans was far less (5)____. Research on the malaria vaccine arouses (6)____ interest in African, Asian, and South American countries, where malaria is (7)____ a most dangerous disease causing (8)____ loss of life and (9)____ problems. Everybody is then (10)____ waiting for good news about (11)____ trails of a new medicine as the future costs of malaria spreading are indeed (12)____.

1 – infect, 2 – prevent, 3- science, 4- effect, 5 – impress, 6 – consider, 7 – economy, 8 – patience, 9 – economy, 10 – patience, 11 – success, 12 – predict.