The UK and other leading industrialised nations are setting up a £750m ($1.5bn) fund to speed up the development of new vaccines for use in poorer countries.
Developing countries need specially-tailored jabs for some diseases
The plan is to subsidise the future purchase of vaccines in the hope this will galvanise drug firms into action.
A vaccine for pneumococcal disease is the first target.
A jab already exists, but developing countries need a tailored version which firms have been slow to invest in as there is no guaranteed market.
Developing countries need their own vaccines as the strains of the infections vary from many western countries.
The idea of the fund is to act as a bridge between poorer countries and drug firms.
If a developing country agrees it needs a drug which industry can develop, the fund provides a commitment to purchase the vaccines once they are produced.
Chancellor Gordon Brown will be at the launch of the fund, the so-called Advance Market Commitment, in Rome on Friday along with World Bank officials and ministers from other G7 countries.
The UK is set to contribute £200m ($400m) towards the fund.
While pneumococcal disease - which causes meningitis and pneumonia and is responsible for two million child deaths a year - is the first aim, officials are hoping to see vaccines developed for malaria, HIV/Aids and tuberculosis.
Dr Orin Levine, one of the officials behind the scheme, said the fund would act as an important incentive to the industry.
"When you say that pneumonia is one of the leading infections worldwide, people are surprised to hear that.
"But it is right up there with malaria."
Jeffrey Mecaskey, head of health at Save the Children, said: "This will help provide new vaccines and drugs and start to overcome the 10:90 divide - over 90% of drug investments go on the diseases affecting the richest 10% of people.
"However, despite the great strides from this investment, political and financial support must go beyond developing and buying drugs.
"Clinics need to be built, doctors and nurses trained and fees for medical treatment scrapped so people can afford to seek medical help in the first place.
"Without the Chancellor's commitment will be compromised and will make little difference to the children and families who would benefit."