mRNA vaccine effectiveness against hospitalisation due to severe acute respiratory infection (SARI) COVID-19 during Omicron variant predominance estimated from real-world surveillance data, Slovenia, February to March 2022 Grgič Vitek, Marta and Klavs, Irena and Učakar, Veronika and Vrh, Marjana and Mrzel, Maja and Serdt, Mojca and Fafangel, Mario, Eurosurveillance, 27, 2200350 (2022), https://doi.org/10.2807/1560-7917.ES.2022.27.20.2200350