Vaccines against H.I.V., malaria and tuberculosis — three major killers of the world’s poor — are unlikely to be produced in the foreseeable future unless vastly more money is committed to finding them, a new study has concluded.

Other worthy goals that appear out of reach for now include a hepatitis C vaccine, a combination vaccine against the four leading causes of deadly diarrhea, a rapid cure for people who have caught tuberculosis and new treatments for a dozen neglected diseases, such as leprosy, dengue fever and sleeping sickness.

To make real progress against this variety of infectious diseases by 2030, the study concluded, the world must increase research spending to nearly $9 billion a year; it now spends only about $3 billion.

But the world is moving in the opposite direction. The combined amount that government donors, private foundations and pharmaceutical companies spend on the cause soared in the early 2000s. But, except for some recent emergency funding of Ebola research, it has slowly declined since the 2009 fiscal crisis.