Four out of five women in the UK have now received a silver bullet - the HPV vaccine that prevents cervical cancer. Thanks to a national effort to vaccinate girls and young women, HPV infections among women aged 16 to 21 have significantly dropped.

This is not surprising. We know that we could prevent an estimated 90% of cervical cancers worldwide simply by vaccinating young girls against HPV infection. Yet more countries celebrate Mother’s Day than run HPV vaccination campaigns. In the US, only three out of five kids receive the vaccine. And just 80 countries - little more than 40% of the world - have immunization programmes that include the HPV vaccine.

Cervical cancer kills more than 250,000 women every year. Nine out of every ten of those women live in developing countries. It is the leading cause of cancer death for women in Sub-Saharan Africa. Too often, by the time the disease is identified, there is no hope of cure. Many of these women never even become patients.

We know that most people - men and women - will have an HPV infection in their lifetime. While the vast majority of infections clear on their own, those that don’t can turn into cancer. We know too that people whose immune systems have been compromised - by malaria or HIV, for example - could have a more difficult time clearing the infection from their bodies, and therefore a higher likelihood of developing cancer.

But we don't know for certain whose infections will not clear, instead turning into cancer. This is why the World Health Organization (WHO) recommends that children between the ages of 9 and 14 get vaccinated against HPV. This point was driven home in May by WHO Director General Dr. Tedros Adhanom, when he called for a coordinated global campaign to eliminate cervical cancer. This came ten days after the publication of a review of 26 studies involving 70,000 women around the world which reinforced the effectiveness of the HPV vaccine in preventing cervical cancer.

In 2011, Rwanda - the first country in Sub-Saharan Africa to roll out the vaccine nationally - negotiated with vaccine manufacturer Merck to acquire a three-year supply at no cost, then a continued supply at a reduced cost. Because the vaccine was intended for 11-12 year-olds, it was administered through schools instead of through clinics, as is the case for routine immunizations intended for infants and much younger children. Extensive community outreach made clear that the vaccine would prevent cancer. This resulted in more than 93% coverage.

Image: Cervical Cancer Action

This outreach was key to the success of the roll-out in Rwanda, incorporating a wide range of community leaders not routinely involved with immunization services. But these successes have been difficult to replicate. Rwanda’s neighbour to the north, Uganda, has struggled to deliver the second dose of the vaccine to everyone who received the first dose.

WHO’s expanded efforts on vaccination and screening are welcome around the world as several countries roll out HPV vaccination programmes this year, including Tanzania, Zimbabwe and Ethiopia. Even with assistance from Gavi (the international vaccine assistance programme for low-income countries) and the Pan American Health Organization (PAHO) Revolving Fund, the cost of delivering the HPV vaccine puts a serious burden on a country’s health system. And middle-income countries, which are too wealthy to get support but not wealthy enough to afford the vaccine, are left to figure out the logistics of vaccinating their adolescents on their own.

We should not give up hope. In 1990, more than half a million women died because of complications in pregnancy and childbirth. After international attention and resources focused on lowering that unacceptable number, by 2015 maternal mortality dropped by 44%. More women now die from breast and cervical cancers than from complications in pregnancy and childbirth. This should not be so for cervical cancer, which is both preventable and treatable if detected early.

We are losing too many women in the prime of their lives, because of the age at which cervical cancer strikes. There is only one way to inoculate ourselves from these tragedies - the HPV vaccine.

Ambassador Sally G. Cowal is the Senior Vice President, Global Cancer Control, at the American Cancer Society. She helped found the Joint United Nations Program on HIV/AIDS (UNAIDS) in Switzerland and served as U.S. Ambassador to the Republic of Trinidad and Tobago, appointed by former Presidents George H.W. Bush and William J. Clinton.