N. Samieefar, R. Rashedi, M. . Akhlaghdoust, M. Mashhadi, P. Darzi, and N. Rezaei, “Delta Variant: The New Challenge of COVID-19 Pandemic, an Overview of Epidemiological, Clinical, and Immune Characteristics”, Acta Biomed, vol. 93, no. 1, p. e2022179, Mar. 2022, doi: 10.23750/abm.v93i1.12210.