A single-dose live-attenuated YF17D-vectored SARS-CoV2 vaccine candidate

Felipe, Lorena Sanchez; Vercruysse, Thomas; Sharma, Sapna; Ma, Ji; Lemmens, Viktor; van Looveren, Dominique; Arkalagud Javarappa, Mahadesh Prasad; Boudewijns, Robbert; Malengier-Devlies, Bert; Kaptein, Suzanne F.; Liesenborghs, Laurens; De Keyzer, Carolien; Bervoets, Lindsey; Rasulova, Madina; Seldeslachts, Laura; Jansen, Sander; Yakass, Michael Bright; Quaye, Osbourne; Li, Li-Hsin; Zhang, Xin; Horst, Sebastiaan ter; Mishra, Niraj; Coelmont, Lotte; Cawthorne, Christopher; Van Laere, Koen; Opdenakker, Ghislain; Van de Velde, Greetje; Weynand, Birgit; Teuwen, Dirk E.; Matthys, Patrick; Neyts, Johan; Thibaut, Hendrik Jan; Dallmeier, Kai

The explosively expanding COVID-19 pandemic urges the development of safe, efficacious and fast-acting vaccines to quench the unrestrained spread of SARS-CoV-2. Several promising vaccine platforms, developed in recent years, are leveraged for a rapid emergency response to COVID-191. We employed the live-attenuated yellow fever 17D (YF17D) vaccine as a vector to express the prefusion form of the SARS-CoV-2 Spike antigen. In mice, the vaccine candidate, tentatively named YF-S0, induces high levels of SARS-CoV-2 neutralizing antibodies and a favorable Th1 cell-mediated immune response. In a stringent hamster SARS-CoV-2 challenge model2, vaccine candidate YF-S0 prevents infection with SARS-CoV-2. Moreover, a single dose confers protection from lung disease in most vaccinated animals even within 10 days. These results warrant further development of YF-S0 as a potent SARS-CoV-2 vaccine candidate.