Perez-Florido J, Casimiro-Soriguer CS, Ortuno F, et al. Detection of High Level of Co-Infection and the Emergence of Novel SARS CoV-2 Delta-Omicron and Omicron-Omicron Recombinants in the Epidemiological Surveillance of Andalusia. Int J Mol Sci. 2023;24(3). doi:10.3390/ijms24032419.