A study published in the New England Journal of Medicine demonstrated that one dose of HPV vaccine is non-inferior (noninferior) compared to two doses in terms of immunological response. The results showed that antibody levels against HPV 16 and HPV 18 after one dose were comparable to those after two doses, with protection maintained over the study period. In one analysis, the response to one dose was similar to that to two doses, with both regimens yielding significantly higher antibody titers than in unvaccinated subjects. The efficacy of a single dose was rated high in some studies, with long-term protection against oncogenic HPV genotypes. These findings suggest the possibility of simplifying the vaccination schedule, which could increase vaccination availability and coverage. But the study doesn't say that one dose is exactly the same as the three doses that are standard for older age groups. The results support a reconsideration of HPV vaccination recommendations, especially in younger individuals.