Business Administration student David Teng has the best idea to increase willingness for vaccinations in the Netherlands. Together with his niece Yeewah Chong (UvA student), he came up with ‘Covid-19 Opt-out system’, a system that should make vaccination planning much easier. With the idea they won the "Covid Behavioral Challenge", launched by the Dutch government.The third prize was won by the idea for a vaccination buddy-campaign of Jari HoogstinsOpens external (researcher at ECRiOpens external), Emiel MaaslandOpens external (managing director of ECRi) and Inge Merkelbach (behavioral scientist at Erasmus School of Social and Behavioural Sciences).