A single-dose live-attenuated YF17D-vectored SARS-CoV-2 vaccine candidate

Lorena Sanchez-Felipe, Thomas Vercruysse, Sapna Sharma, Ji Ma, Viktor Lemmens, Dominique Van Looveren, Mahadesh Prasad Arkalagud Javarappa, Robbert Boudewijns, Bert Malengier-Devlies, Laurens Liesenborghs, Suzanne J F Kaptein, Carolien De Keyzer, Lindsey Bervoets, Sarah Debaveye, Madina Rasulova, Laura Seldeslachts, Li-Hsin Li, Sander Jansen, Michael Bright Yakass, Babs E VerstrepenKinga P Böszörményi, Gwendoline Kiemenyi-Kayere, Nikki van Driel, Osbourne Quaye, Xin Zhang, Sebastiaan Ter Horst, Niraj Mishra, Ward Deboutte, Jelle Matthijnssens, Lotte Coelmont, Corinne Vandermeulen, Elisabeth Heylen, Valentijn Vergote, Dominique Schols, Zhongde Wang, Willy Bogers, Thijs Kuiken, Ernst Verschoor, Christopher Cawthorne, Koen Van Laere, Ghislain Opdenakker, Greetje Vande Velde, Birgit Weynand, Dirk E Teuwen, Patrick Matthys, Johan Neyts, Hendrik Jan Thibaut, Kai Dallmeier

Research output: Contribution to journalA1: Web of Science-articlepeer-review


The expanding pandemic of coronavirus disease 2019 (COVID-19) requires the development of safe, efficacious and fast-acting vaccines. Several vaccine platforms are being leveraged for a rapid emergency response1. Here we describe the development of a candidate vaccine (YF-S0) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that uses live-attenuated yellow fever 17D (YF17D) vaccine as a vector to express a noncleavable prefusion form of the SARS-CoV-2 spike antigen. We assess vaccine safety, immunogenicity and efficacy in several animal models. YF-S0 has an excellent safety profile and induces high levels of SARS-CoV-2 neutralizing antibodies in hamsters (Mesocricetus auratus), mice (Mus musculus) and cynomolgus macaques (Macaca fascicularis), and-concomitantly-protective immunity against yellow fever virus. Humoral immunity is complemented by a cellular immune response with favourable T helper 1 polarization, as profiled in mice. In a hamster model2 and in macaques, YF-S0 prevents infection with SARS-CoV-2. Moreover, a single dose conferred protection from lung disease in most of the vaccinated hamsters within as little as 10 days. Taken together, the quality of the immune responses triggered and the rapid kinetics by which protective immunity can be attained after a single dose warrant further development of this potent SARS-CoV-2 vaccine candidate.

Original languageEnglish
Issue number7845
Pages (from-to)320-325
Number of pages6
Publication statusPublished - 2021
Externally publishedYes


  • Animals
  • COVID-19/immunology
  • COVID-19 Vaccines/administration & dosage
  • Cricetinae
  • Disease Models, Animal
  • Female
  • Genetic Vectors/genetics
  • Glycosylation
  • Macaca fascicularis/genetics
  • Male
  • Mesocricetus/genetics
  • Mice
  • SARS-CoV-2/immunology
  • Safety
  • Spike Glycoprotein, Coronavirus/chemistry
  • Vaccines, Attenuated/administration & dosage
  • Yellow Fever Vaccine/genetics

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