1. Bundesministerium für Gesundheit. Nationale Impfstrategie: Strategie zur Einführung und Evaluierung einer Impfung gegen Sars-CoV-2 in Deutschland. [April 14, 2021]; Available from: https://www.bundesgesundheitsministerium.de/fileadmin/Dateien/3_Downloads/C/Coronavirus/Impfstoff/Nationale_Impfstrategie.pdf.
2. World Health Organization. Coronavirus disease (COVID-19): Herd immunity, lockdowns and COVID-19: What is ‘herd immunity’? [September 27, 2021]; Available from: https://www.who.int/news-room/q-a-detail/herd-immunity-lockdowns-and-covid-19.
3. Herd Immunity: Understanding COVID-19;Randolph;Immunity,2020
4. SARS-CoV-2: from herd immunity to hybrid immunity;Goldblatt;Nat Rev Immunol,2022
5. Five reasons why COVID herd immunity is probably impossible;Aschwanden;Nature,2021