Evaluating the Effectiveness of Pfizer, AstraZeneca, and Sinopharm Vaccines Against COVID-19 in Iraq: A Cross-Sectional Study of Vaccine Efficacy and Symptom Severity. Journal of Madenat Alelem, [S. l.], v. 16, n. 1, p. 11–21, 2024. Disponível em: https://journal.mauc.edu.iq/index.php/JMAUC/article/view/507. Acesso em: 25 feb. 2026.