At the same time, health systems need significant strengthening. External assistance will be critical for countries that do not have enough domestic resources to finance the spending required. Vertical interventions should continue to be harmonized with the horizontal health system so that the former do not weaken the latter, but instead strengthen it. The world has seen a reduction in under-five, maternal and malaria-related mortality rates and the number of new HIV/AIDS infections, as well as an increase in the number of lives saved through improvements in testing and treatment of tuberculosis.