Requejo said that even before the pandemic, coverage rates of vaccination for DTP had stagnated in part because of rapidly increasing population numbers in key countries. “There are some regions, like Africa, where you have an increasing birth cohort. So 85 percent coverage in 2008 is X number of people, but its X plus a couple of million more that you need to deliver just to maintain that level,” Requejo said.
The U.N. Population Division estimated Monday that the world’s population will reach 8 billion later this year. Some of the countries expected to see their population increase dramatically, such as Nigeria and the Democratic Republic of Congo, already have millions of unvaccinated children. Both are expected to see their population grow by well over 100 million by 2050.