Bill Gates is promoting a plan to use wireless technology to register every newborn on the planet in a vaccine database.

In a keynote address to the mHealth Summit, which focuses on using mobile technology to improve health care, Gates said that improving survival rates among children under the age of 5 would benefit not just individual families, but societies and the planet as a whole.

“The key thing, the most important fact that people should know and make sure other people know: As you save children under 5, that is the thing that reduces population growth,” he said. “That sounds paradoxical. The fact is that within a decade of improving health outcomes, parents decide to have less children.”

The number of children who die before their fifth birthday has already dropped from 20 million in 1960 to 8.5 million today, a statistic Gates attributes mostly to vaccination.