HPV Vaccine Protects the Unvaccinated, Study Shows

By Adebowale Bello. B.Tech Microbiology, Freelance Health Writer. Medically reviewed by the DLHA team.

November 18, 2025

Two vials of HPV vaccines and a syringe with a covered needle.

When the human papillomavirus (HPV) vaccine was first rolled out nearly two decades ago, many people wondered if it would truly make a lasting difference. HPV is one of the most common sexually transmitted infections in the world and is responsible for most cases of cervical cancer, along with some anal, throat and genital cancers. It affects both men and women, but its consequences are often more severe for women, especially in regions where screening and treatment are limited.

Seventeen years later, new research shows just how powerful the HPV vaccine has become. The study reveals that the vaccine doesn’t only protect those who receive it, it also protects others who haven’t been vaccinated. This indirect protection, known as “herd protection,” is an encouraging sign that the vaccine is reshaping the landscape of HPV infection globally.

For African countries where cervical cancer remains one of the deadliest yet preventable diseases among women, these findings bring renewed hope. They show that vaccination can go beyond individual benefit to transform public health outcomes at a national and even continental level.

About the Study

Researchers in the United States followed sexually active girls and young women aged 13 to 26 over 17 years, from 2006 to 2023. They wanted to see how effective the vaccine has been in real life, beyond the early trials. They also looked for signs of herd protection, meaning whether unvaccinated people benefit when more people around them are vaccinated.

The team collected data in six waves between 2006 and 2023, covering the period when the HPV vaccine went from being new to widely available. In total, 2,335 participants were included and some had received the vaccine, while others had not. The scientists tested these participants for different strains of HPV, including the ones targeted by the 2-valent, 4-valent and 9-valent vaccines.

By comparing infection rates among vaccinated and unvaccinated individuals across these time periods, the researchers could determine how well the vaccine was working in the real world. They also examined whether unvaccinated people were showing lower infection rates over time which would be an indication of herd protection.

What the Study Found

Among those who had received the vaccine, infection rates for HPV types covered by the vaccine dropped dramatically.

For instance, infections with the two-valent HPV types fell from nearly 28% in the early years of the study to less than 1% after 17 years. Similar declines were seen for the four-valent and nine-valent vaccine types.

Even more impressive was what happened among those who had never been vaccinated. Their infection rates also dropped significantly—by more than 70% for the HPV types covered by the original vaccine. This showed that widespread vaccination reduced the overall presence of these viruses in the community, making it harder for them to spread even to unvaccinated people.

In short, the more people got vaccinated, the less chance the virus had to circulate. The study provides strong evidence that the HPV vaccine works not only at the individual level but also at the population level, creating a safety net that protects everyone.

What the Study Means for Africans

Cervical cancer remains one of the top causes of cancer-related deaths among African women. This study shows that HPV vaccination works and the sooner it is scaled up, the more lives it will save.

Many African countries have started introducing the HPV vaccine into their national immunisation programmes. Nigeria, Ghana, Kenya, Mozambique and South Africa are some examples but coverage is still low in several regions, especially in rural communities. Many girls never receive the vaccine due to factors such as poor awareness, limited access to healthcare facilities, cultural myths or vaccine hesitancy.

If African countries can achieve high vaccination rates, the benefits seen in this study could be replicated—reducing HPV infections and future cervical cancer cases. It also shows that even when not everyone is vaccinated, communities can still benefit if enough people receive the vaccine.

Why Herd Protection Matters

Herd protection is a critical concept for public health. When enough people are vaccinated, viruses find it harder to spread. This protects those who cannot get vaccinated for medical or social reasons. For HPV, this means even unvaccinated women—and eventually men—can see lower risks of infection.

While cervical cancer is the most well-known disease linked to HPV, the virus can also cause other cancers and genital warts in both men and women. By reducing HPV infections, the vaccine helps to prevent these conditions too. For African health systems already burdened with limited resources, prevention through vaccination is far cheaper and more effective than treatment. Once cervical cancer develops, treatment costs are high, and survival chances are often low, especially where screening and oncology services are limited. The HPV vaccine offers a powerful preventive tool that can ease this burden.

Wrap Up

Seventeen years after the HPV vaccine’s introduction, its success story continues to grow. It has proven effective in reducing HPV infections and protecting communities through herd protection. The evidence shows that vaccination works and herd protection is real.

Scaling up HPV vaccination in African countries could prevent thousands of deaths every year and change the future of women’s health on the continent. It’s time for governments, communities and individuals to work together to make the HPV vaccine widely available, because every country that prioritises HPV vaccination is not just protecting today’s girls but safeguarding the next generation from preventable cancer.

Source: DeSieghardt A, Ding L, Ermel A, et al. Population-Level Effectiveness and Herd Protection 17 Years After HPV Vaccine Introduction. JAMA Pediatr. Published online September 29, 2025. Available from here

Related:

Why African Girls Need the HPV Vaccine

Cervical Cancer Screening Information for African women

Cervical Cancer: What African Women Need to Know

Published: November 18, 2025

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