The Gates Foundation said on Tuesday it will commit $1.6 billion over the next five years to support Gavi, a public-private partnership that helps buy vaccines for the world's poorest children.

U.S. Health Secretary Robert F. Kennedy Jr. says the country is ending support for the international vaccine alliance Gavi.

The Gates Foundation has announced a $1.6 billion commitment to Gavi, the Vaccine Alliance, over the next five years — a major boost to efforts aimed at protecting millions of children in the world’s poorest countries from preventable diseases.