COVID-19 Vaccine Effectiveness Studies against Symptomatic and Severe Outcomes during the Omicron Period in Four Countries in the Eastern Mediterranean Region oleh Manuela Runge, Zahra Karimian, Mehrnaz Kheirandish, Giulio Borghi, Natalie Wodniak, Kamal Fahmy, Carsten Mantel, Thomas Cherian, Zeinab Nabil Ahmed Said, Farid Najafi, Fatima Thneibat, Zia Ul-Haq, Sheraz Fazid, Iman Ibrahim Salama, Fatemeh Khosravi Shadmani, Ahmad Alrawashdeh, Shadrokh Sirous, Saverio Bellizzi, Amira Ahmed, Michael Lukwiya, Arash Rashidian, on behalf of the Consortium of Authors