HPV Vaccine Update: Why the Dose Schedule Was Modified (Part 1)

The HPV vaccine is a powerful tool used to prevent diseases, particularly cervical cancer, caused by the human papillomavirus. When the vaccines were first approved for public use between 2006 and 2014, the standard hpv vaccine dose schedule was rigorous. Generally, children aged 9 to 14 years received two doses, while individuals aged 15 and above were required to take three doses.

However, in 2022, the World Health Organization (WHO) updated these recommendations, suggesting fewer doses for specific age groups. Why was this change made? Extensive global research has revealed that fewer doses can be just as effective. Here is the science behind the new HPV vaccine guidelines.

HPV vaccine dose: Strong Immune Defense in Younger Girls

One of the key reasons for the change came from a major research in Canada. Scientists discovered that girls aged 9 to 13 who received just two doses of the HPV vaccine developed an immune defense that was non-inferior to—and in some cases better than—young women aged 16 to 26 who received the standard three doses.

In fact, the study showed that the younger girls produced significantly higher levels of virus-fighting antibodies after two doses compared to the older group after three. This suggested early on that younger immune systems respond very robustly to the vaccine.

Evidence from Large International Trials

Further evidence emerged by combining results from a large international trial (PATRICIA) and a specific vaccine trial in Costa Rica. Researchers tracked over 26,000 women for four years to see how well the vaccine worked in real-world scenarios.

The findings were groundbreaking: receiving just one or two shots of the HPV vaccine was as effective at protecting against the main cancer-causing virus types (HPV 16 and 18) as the standard three-shot schedule. This indicated that a reduced schedule could still offer high levels of protection.

The Power of a Single Dose

More recent studies have focused specifically on the efficacy of a single hpv vaccine dose. A pivotal study involving over 2,000 young women in Kenya found that receiving just a single shot of the HPV vaccine is incredibly effective.

Over the course of 18 months, the researchers found that one dose stopped 97.5% of dangerous, cancer-causing virus infections. This demonstrated that a single dose provides powerful protection, comparable to multidose regimens, for those who might otherwise go unvaccinated.

You can read the part two of the article here. To learn more about HPV message us on WhatsApp by clicking the icon on the bottom right of the page. You can consult a doctor to know if you’re eligible for the HPV vaccination here.