The World Health Organization (WHO) prioritizes diseases caused by viral infections as a major public health risk due to their epidemic potential and the current lack of effective countermeasures. DNDi is contributing to this global effort through the development of effective interventions to control severe emerging infectious diseases, including antiviral therapy targeting several families of viruses.

The Nucleoside Booster project is a partnership between DNDi and the German Center for Infection Research (DZIF). The project involves the systematic assessment of a collection of 145 nucleoside drugs to determine broad-spectrum antiviral activity in a wide panel of in vitro cellular assay systems. The goal of the project is to identify new candidates with broad-spectrum antiviral profiles suitable for further development.

Nucleoside analogues have shown remarkable success in antiviral drug development. Multiple nucleoside analogue drugs are currently used in the treatment of serious viral infections, including abacavir (HIV), sofosbuvir (hepatitis C), remdesivir (Ebola), and more recently, molnupiravir (COVID-19).

DNDi is responsible for selecting and sourcing nucleoside drugs for testing by the Antiviral Compound Testing Platform (ACTP) established by DZIF and headed by Heidelberg University Hospital (UKHD). The ACTP is supported by the Helmholtz Centre for Infection Research (HZI) and the University of Hamburg in the areas of substance logistics and nucleoside chemistry.

Viruses recognised by WHO as presenting the greatest epidemic and pandemic potential in humans – and identified as priorities for pharmaceutical research and development – are included in the project. The results of these studies will be made public through open access channels to advance pharmaceutical research and development in the area of pandemic preparedness.

Project updates


A total of 128 nucleosides were physically secured for the project and six laboratories via the Helmholtz Centre for Infection Research. The compounds were sourced through collaboration with the Calibr-Skaggs Institute for Innovative Medicines  and from vendors. A first report of the primary screening data for 116 compounds was received in September 2023. Four nucleosides with broad-spectrum antiviral activity and 19 nucleosides with restricted antiviral activity were identified in the report and physically resupplied to partner laboratories for further testing in December 2023.