Neglected Tropical Diseases (NTDs) are a group of diseases that are highly prevalent in tropical and subtropical regions, and closely associated with poverty and marginalized populations. Infectious diseases affect over 1.6 billion people annually, and vaccines are the best prophylactic tool against them.
Despite advancement in global pharmaceutical research, the development of new vaccines for tropical diseases remains difficult.
To stimulate the development of vaccines therapeutics for tropical diseases, the FDA created`Neglected Tropical Disease Priority Review Voucher Program’
Under this system, a company that receives approval for a product to treat or prevent a neglected tropical disease receives a `Priority Review Voucher (PRV)`. With this voucher, the company can, for a drug or vaccine of their choice, request a review under FDA’s Priority Review Designation pathway. This pathway enables FDA review of a New Drug Application (NDA) / Biological Licence Application (BLA) in just six months instead of the standard ten-month time period.
The priority review voucher system was first mentioned in a March 2006 paper (Ridley et al, 2006). In their paper Ridley et al, proposed the creation of a priority voucher system specifically targeted at neglected tropical diseases, which the authors argued lacked sufficient development incentives to produce. They proposed this ’incentive’, could be used in one of two ways: either it could be redeemed by its recipient, or it could be sold to another company, which might want to have its own drug reviewed in a six-month timeframe.
The initiative caught the attention of legislators and was integrated into the Food and Drug Administration Amendments Act (FDAAA) of 2007.
The policy contains a list of eligible tropical diseases. Most diseases were included in September 2007, with an additional number added in 2014, 2015, 2016, and 2018. It is possible to request for additional diseases to be included in the lsit.
Table 1 Diseases in included in the PRV program
The voucher can only be awarded to products (drugs, vaccines, and devices) for one of the eligible diseases and for which one or more new clinical investigations (other than bioavailability studies) that are essential to the approval of the application have conducted or sponsored by the sponsor.
In addition, the applicant must provide in the application an attestation that such studies were not submitted as part of an application for marketing approval or licensure by a regulatory authority in India, Brazil, Thailand, or any country that is a member of the Pharmaceutical Inspection Convention or the Pharmaceutical Inspection Cooperation Scheme prior to September 27, 2007.
The product itself must otherwise qualify for priority review, and must contain no active ingredient (including any salt or ester of an active ingredient) that has been approved in any other application, although combination products with at least one new active moiety are eligible).
The tropical disease priority review voucher may be sold or transferred to a third party an unlimited amount of times.
Similar voucher programs exist for products being developed for Rare Pediatric Diseases and products being developed for Medical Countermeasures. The rare pediatric disease priority review voucher program was not renewed at the end of 2024 however. Earlier this year The FDA introduced the FDA Commissioner's National Priority Voucher (CNPV) pilot program for addressing US national priorities, like addressing a health crisis in the U.S. These vouchers will however not be transferable.
Up to date 15 Neglected Tropical Diseases Vouchers have been awarded, with the last one being handed out to Bavarian Nordic for their VIMKUNYA™ Chikungunya vaccine. This voucher was sold for 160 million USD in June 2025.
Table 2 Overview of awarded Neglected Tropical Disease Vouchers
References:
Food and Drug Administration Guidance for Industry - Tropical Disease Priority Review Vouchers
Ridley DB, Grabowski HG, Moe JL. Developing drugs for developing countries. Health Aff (Millwood). 2006 Mar-Apr;25(2):313-24. doi: 10.1377/hlthaff.25.2.313. PMID: 16522573.
Food and Drug Administration Commissioner's National Priority Voucher (CNPV) Pilot Program | FDA
Bavarian Nordic News | Bavarian Nordic
