* Health experts say "grand convergence" possible by 2035
* Investment needs to focus on R&D, drugs and vaccines
* Taxes on tobacco, alcohol and sugar also recommemded
By Kate Kelland
LONDON, Dec 3 (Reuters) - Health disparities between rich and poor nations could be banished in a generation by investment in research, vaccines and drugs to combat diseases such as AIDS, malaria and tuberculosis, global health experts said on Tuesday.
In a report setting out a plan for a "grand convergence" in health, the experts said world leaders needed to press for a concerted increase in research and development (R&D) investment to develop new medicines, vaccines and health technologies.
"For the first time in human history, we are on the verge of being able to achieve a milestone for humanity: eliminating major health inequalities...so that every person on earth has an equal chance at a healthy and productive life," said Larry Summers, a former U.S. Treasury Secretary who co-chaired a commission on global health.
The report also recommended taking bold preventative steps in public health, such as increasing taxes on tobacco and other substances that can be harmful, like alcohol and sugar.
Taking China as an example, it said a 50 percent tax on tobacco could prevent 20 million premature deaths and generate an extra $20 billion annually over the next 50 years.
Summers said effective drugs and vaccines now available "make reaching this milestone affordable" and urged world leaders to take on what he called "our generation's unique opportunity to invest in making this vision real".
The report, called "Global Health 2035: A World Converging within a Generation" was written by 25 leading international health experts and economists, chaired by Summers, of Harvard University, and published in The Lancet health journal.
It said spending should be prioritised in key areas, including aggressively scaling up new and existing medicines and policies for HIV and AIDS, tuberculosis, malaria, neglected tropical diseases and maternal and child health.
The report's authors said that if their recommendations were followed, roughly 10 million lives could be saved in low-income and middle-income countries in the year 2035 alone - progress that would bring enormous social and economic gains for the countries most affected.
To get to such a point, global investment in R&D needs to be at least doubled, the experts said, from around $3 billion a year now to $6 billion by 2020. Half of that increased investment would need to come from middle-income countries.
"The role of international assistance, while still vital, is going to increasingly emphasise scientific research, provide templates and models that can be emulated, and focus on development of techniques and dissemination of information," Summers said in a statement issued with the report.
He said while aid would remain critical it should become "less about financial support to individual countries and more about the provision of global public goods".
Richard Horton, The Lancet's editor and another of the report's authors, said the world should recognise that investing in health is also an investment in prosperity, social and financial protection, and national security.
"Investing in health means investing in a quality human beings value deeply, but which we do not capture well in our usual measures of development," he said. (Reporting by Kate Kelland; editing by Ralph Boulton)