Dear Dr G,I am a mother of two teenagers who are just starting secondary school.I received paperwork from the school health department asking for consent for HPV vaccinations for both children.Of course, I completely agree my 13-year-old daughter should be protected against cervical cancer.I also see the benefit of my 12-year-old son receiving the vaccine for protection against rare HPV-related male cancers.I am more intrigued by the leaflet highlighting the role of vaccination in boys helping to build herd immunity in the overall elimination of cervical cancer.I understand achieving high vaccination coverage is not always possible.Therefore, I am curious about the current overall protection a girls-only vaccination programme provides in achieving cervical cancer elimination goals.Therefore, I would like to put Dr G on the spot for clarification on gender-neutral vaccination.Can you give me some idea of protection against cervical cancer when vaccination coverage is low in a girls-only programme?Furthermore, can you outline the differences in coverage and herd immunity when coverage is higher?Lastly, can high vaccination coverage really result in complete elimination of HPV-related cancers in both genders?Yours truly,Protective Pamela Human papillomavirus (HPV) is responsible for nearly all cases of cervical cancer and contributes to a growing number of other cancers affecting both women and men. The introduction of HPV vaccines has transformed the landscape of cancer prevention, offering the possibility of dramatically reducing and potentially eliminating these diseases. Early vaccination programmes focused primarily on girls, with the rationale that protecting females directly would reduce cervical cancer and indirectly protect the wider population through herd immunity. While this approach has produced meaningful reductions in HPV prevalence and disease, it has become increasingly clear that relying on girls-only vaccination is not sufficient to achieve long-term elimination of HPV-related cancers. The effectiveness of HPV vaccines at the individual level is well established. When administered before exposure to the virus, they can greatly reduce the risk of cervical cancer. In a girls-only vaccination programme, the overall reduction in cervical cancer depends on both vaccine efficacy and the proportion of girls vaccinated. If coverage reaches 80%, then direct protection alone would be expected to reduce cervical cancer incidence by about 93%. At this level of uptake, herd immunity begins to play a role, as fewer infections circulate within the population. Although this level of reduction is substantial, it falls short of elimination. More importantly, the virus continues to circulate among males, who are not protected in a girls-only programme and can transmit HPV back to women. This ongoing transmission limits the extent of herd immunity and prevents the complete interruption of the virus’s spread. The limitations of girls-only vaccination become even more apparent when coverage is lower. At 40% coverage, direct protection reduces cervical cancer risk by approximately 53%. Herd immunity at this level is weaker because a larger proportion of the population remains susceptible, and transmission chains are less disrupted. In this scenario, nearly half of cervical cancer cases would still occur, and HPV would continue to circulate widely within the population. These figures highlight a central problem with relying on herd immunity in girls-only vaccination strategies. Herd immunity is highly sensitive to vaccination coverage and population structure. It assumes relatively uniform uptake and stable transmission patterns. Gender-neutral vaccination offers a more comprehensive solution to these challenges. By vaccinating both girls and boys, the programme provides direct protection to all individuals, rather than relying heavily on indirect effects. This approach reduces the overall circulation of HPV because it targets both sides of the transmission pathway. If coverage reaches 80% in both boys and girls, complete elimination of HPV-related cancers is expected in both genders, including cervical cancers. In addition to strengthening herd immunity, gender-neutral vaccination addresses important issues of equity and disease burden. HPV is not solely a women’s health issue; it also causes cancers in men, including oropharyngeal, anal and penile cancers. A girls-only approach leaves men largely unprotected and fails to address these growing cancer burdens. Furthermore, gender-neutral vaccination reduces the programme’s dependence on uniformly high uptake among girls. In practice, achieving and maintaining coverage above 80% is challenging, particularly in settings with limited healthcare access or vaccine hesitancy. When both sexes are vaccinated, the system becomes more resilient to gaps in coverage, as immunity is distributed more broadly across the population. This resilience is critical for sustaining long-term reductions in HPV transmission and for progressing towards elimination. The ultimate aim of HPV vaccination programmes is not merely to reduce disease but to eliminate HPV-related cancers as a public health problem. While girls-only vaccination has laid an important foundation, its limitations mean it cannot achieve this goal on its own. Even at relatively high coverage levels, significant transmission persists, and substantial numbers of cancers continue to occur. Gender-neutral vaccination, by contrast, offers a more robust and effective pathway to elimination by directly protecting all individuals, reducing transmission more comprehensively, and addressing inequalities in both risk and access to prevention. Gender-neutral vaccination overcomes limitations by strengthening population immunity, protecting both sexes, and accelerating progress towards the elimination of HPV-related cancers. Benjamin Franklin famously said: “One ounce of protection is worth a pound of cure!” Dr G is often put on the spot for his view of how protecting boys against HPV will help to eliminate cervical cancer in girls. His view is: “Every ounce of protection in both genders will definitely be worth the cure of this horrible cancer!”
