“Personally, I would expect a fourth (COVID-19) vaccination.”
Karl Lauterbach (1963) German politician and Federal Minister of Health
Source: Karl Lauterbach (2021) cited in: " Europe debates 4th coronavirus vaccine as German minister backs double booster https://www.politico.eu/article/europe-fourth-coronavirus-vaccine-germany-minister-karl-lauterbach-booster/" in Politico, 23 December 2021.