Vaccines against HIV, 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.

Duke Center for Policy Impact

“The current development pipeline is not likely to give us all the pieces to fight these diseases,” said Gavin Yamey, director of Duke University’s Center for Policy Impact in Global Health and the study’s lead author. “Donors are cutting back on funding at a time when we should be stepping on the gas.”

The study, which assessed 538 products being developed for 35 diseases afflicting the world’s poor, was the first to analyze such a large portfolio.

Asked about it, leaders of two major funders of global health research — the Bill and Melinda Gates Foundation and the National Institute of Allergy and Infectious Diseases — said they agreed with many of its conclusions but thought it was overly pessimistic about prospects for some new inventions, including a tuberculosis vaccine.

The study was funded by the Gates Foundation and the Swiss Agency for Development and Cooperation and published on Gates Open Research, an open access website.

Dr. Trevor Mundel, the foundation’s president for global health, said he thought the study was right that prospects were dim for a fully protective HIV vaccine or for a malaria vaccine that worked for more than six months. But even six months’ protection would keep newborns alive until their immune systems are stronger, he said.

The foundation still hopes to show that booster doses of BCG, a century-old childhood tuberculosis vaccine, can protect adolescents and that a vaccine candidate it is developing with GlaxoSmithKline, the pharmaceutical company, will stop latent tuberculosis from becoming active.

Asked why the foundation would pay for a study that was likely to cast a pall on projects it has poured hundreds of millions of dollars into, Mundel said: “We’re interested in looking at the whole portfolio — it gives you a good baseline.”

Rather than discouraging other donors, “I hope it will encourage them,” he said.

Dr. Anthony S. Fauci, director of the NIAID, agreed with Yamey that the world “is behind on what we need to spend.”

The United States accounts for nearly half the $3 billion the world spends annually on such research, and Fauci’s institute is one of the chief conduits for that money.

But the study’s gloomy conclusions could be misinterpreted, he said. Like Mundel, he argued that even imperfect vaccines could save lives.

“I think the jury’s still out on whether we’ll have a TB vaccine,” he said.

In addition, tests on two new HIV vaccines should be finished by 2021.

“I don’t think we’ll ever get 98 percent protection as we do with measles, but a vaccine with 50 to 60 percent protection is deployable,” he said.

The study did not try to judge the medical value or odds for success of each invention, but assessed where each was in the development pipeline and how much it typically cost to get similar innovations from conception to launch.

On an optimistic note, the study concluded that about 125 new products are likely to be approved in the next 12 years. Over half will be new diagnostic tests, which do not need years of safety testing.

But the winners are also likely to include vaccines against typhoid and staphylococcus, better combinations of existing drugs for malaria, TB and hepatitis C, better drugs for flu and better flu shots for people age 65 and older.