Our worst fear back in 2006-when the human papillomavirus (HPV) vaccine against cervical cancer finally came to market at a whopping $120 per dose-was that the girls who most needed it would be the ones least likely to get it.

More than 85 percent of cervical cancer cases occur in low- and middle-income countries, especially in Africa and Asia. Those same countries find it difficult to offer screening services, like Pap smears and HPV tests, that have nearly eliminated cervical cancer in wealthy countries. How would these countries ever be able to afford an expensive vaccine? Furthermore, could immunization programs geared to vaccinating babies effectively reach young adolescent girls? And would parents' concern about cervical cancer caused by HPV override their hesitation to mention a sexually transmitted infection to their young daughters?

Easing the way for immunization

The GAVI Alliance, an international organization that helps low-resource countries introduce needed new vaccines, greatly eased the first problem when they began offering HPV vaccine in 2012. Using the power of bulk purchasing, GAVI and UNICEF worked together to get the vaccine at a lower price. GAVI offered it to qualified countries for 20 cents a dose-and sometimes for free.

Meanwhile, groundbreaking work by PATH to understand cultural issues and to demonstrate and evaluate strategies for delivering the vaccine helped answer the other questions. Yes, the countries could reach the right girls and yes, once they understood the issue, parents would flock to protect their daughters against a deadly cancer.

Spared from cervical cancer

Our best hopes-that politicians who determine health budgets would be courageous, forward-thinking, and willing to invest in the future of women since it will take decades for the reduction in cancer to be apparent-are now being realized. Although GAVI projected relatively modest demand from countries in the vaccine's initial years-in large part because the countries were busy introducing other important vaccines against severe diarrhea and pneumonia-in fact, applications requesting HPV vaccine began pouring in.

As a result, over the past two years more than 20 low- and lower-middle income countries have been approved by GAVI for HPV vaccine demonstration projects, and four countries in Africa are already introducing the vaccine nationally. Schoolgirls are lining up for shots that will spare them the agonizing deaths they have seen among their grannies, aunties, and moms.

Healthy future for millions of women

As World Immunization Week approaches, I've been thinking about how much this scene has changed in the past decade. Ten years ago there was no HPV vaccine. Now many countries, even low-income ones, are building a healthy foundation for the futures of millions of women-women who are key producers, managers, teachers, and leaders and who deserve the same chance as women in wealthier countries to live free from a deadly yet mostly preventable disease.

Granted, there still is a lot of work to do-not only to ensure that all girls receive the vaccine, but also to make certain that all women are screened for cervical precancer and treated as needed. But it is clear that a base of support is growing among political leaders willing to bring about these changes. And, most importantly, there is strong demand from parents and communities worldwide for a vaccine with the potential to save millions of women in the coming decades.