PEP++: Moving towards a Breakthrough in the Fight Against Leprosy

What is PEP++ and Why is It Important?

PEP++ is a new multi-dose preventive treatment designed to eliminate leprosy infection in individuals before symptoms appear. Unlike the standard Single-Dose Rifampicin (SDR-PEP) treatment, which provides protection of around 60%, PEP++ offers a more comprehensive approach. It gives at-risk individuals – household contacts and blood relatives – an enhanced drug regimen to further reduce their chances of developing the disease. The enhanced regimen is the Rifampicin from SDR-PEP with an additional antibiotic called Clarithromycin.

The PEP++ Field Trial intake was conducted in Bangladesh, India, Nepal, and Brazil. Researchers identified and treated over 169,000 close contacts of leprosy patients. These were people most at risk of infection—family members, neighbours, and others in direct contact with known cases. The goal was to see whether PEP++ could significantly lower the transmission of the disease compared to the standard preventive treatment – SDR-PEP.

Expanding Protection with the Blanket Campaign

While the PEP++ trial focused on high-risk individuals, the project also launched a Blanket Campaign Trial to reach entire communities in highly endemic areas based on new case detection over previous years. This involved door-to-door screenings and mass preventive treatment efforts in areas with high leprosy rates. The outcomes could prove pivotal in reducing transmission:

• 175,000+ community members in high-risk areas received preventive treatment to date with more to come in Bangladesh
• 150 new cases of leprosy were identified early, preventing further transmission
• When combined with the contact tracing efforts, over 330,000 of the highest at-risk population of the six districts involved in the two trials have seen their risk of developing leprosy reduced

This large-scale approach helped close the gaps left by traditional methods, ensuring that more people received treatment before the disease could spread further.

Local Adaptations for Greater Success

Each country participating in the project found ways to improve the process:

• India used a rapid-response model inspired by polio vaccination campaigns, allowing more people to be reached quickly
• Nepal introduced digital mapping tools to track case clusters and optimize resource distribution
• Bangladesh adjusted its approach by conducting community screening camps instead of door-to-door visits, leading to higher treatment acceptance rates

These adaptations showed that flexibility is key to fighting leprosy, ensuring that treatment is both effective and culturally relevant.

The Next Big Step: Monitoring Long-Term Impact

The fight against leprosy doesn’t stop with administering preventive treatment. The next phase of the project involves tracking the long-term effectiveness of PEP++. This includes:

• Following up with treated individuals to see how many remain leprosy-free
• Confirming diagnostic testing using advanced tools like qPCR (quantitative polymerase chain reaction) to detect the presence of leprosy bacteria at a microscopic level
• Conducting a child serosurvey in Bangladesh, where over 6,000 school-aged children will be tested to understand how prevalent infection is in communities

The Future of Leprosy Prevention

The Stop the Transmission of Leprosy! Project has already made significant progress, but sustained global support is needed to fully eliminate the disease. With PEP++ showing promising results, the world is closer than ever to stopping leprosy transmission for good. Continued investment in prevention, early detection, and treatment will ensure that future generations can live in a world without leprosy.