Costa Rica’s landmark HPV trials continue to provide long-term data on single-dose efficacy and durability.
Initial findings show >80% protection against HPV 16/18 infections sustained 10+ years after one dose—comparable to three doses.
The ongoing ESCUDDO trial (20,000 girls) is testing non-inferiority of one vs. two doses, with results expected to guide future global policy.
Primavera and Prisma studies extend research to adolescent and adult women, assessing immunobridging and broader age catch-up strategies.
Comprehensive follow-up (up to 20 years) will clarify antibody persistence and inform WHO vaccine schedule recommendations.
These studies are pivotal in supporting simplified, cost-effective approaches for global cervical cancer elimination.