Are vaccine shortages a relevant public health issue in Europe? A survey amongst countries participating in the EU-Joint Action on Vaccination, 2019. (December 2020) - Filia, A.; Rota, M.C.; Grossi, A.; Martinelli, D.; de Graaf, T.; Dominguez, A.; Tuells, J.; Sormunen, P.; Jønsrud, K.; Johansen, K.; Chene, G.; Rezza, G.