Bill Gates said he's committed to making sure that the poorest children have the same access to needed vaccines as their wealthy counterparts.
The Microsoft founder pledged $1 billion to help vaccinate children against preventable diseases, according to the BBC.
Gates also asked countries around the world to pitch in $3.7 billion towards vaccine equality by 2015.
The Global Alliance on Vaccines and Immunization (GAVI) said the effort could help save four million lives in four years.
GAVI's site notes that the organization provides "accelerated access" to vaccines for diseases such as yellow fever and Hepatitis B.