RT Journal Article T1 Early SARS-CoV-2 Reinfections Involving the Same or Different Genomic Lineages, Spain A1 Rodríguez Grande, Cristina A1 Estévez, Agustín A1 Palomino Cabrera, Rosalía A1 Molero Salinas, Andrea A1 Peñas Utrilla, Daniel A1 Herranz, Marta A1 Sanz Pérez, Amadeo A1 Alcalá, Luis A1 Veintimilla, Cristina A1 Catalán Alonso, Pilar A1 Martínez Laperche, Carolina A1 Alonso Fernández, Roberto Alfonso A1 Muñoz García, Patricia Carmen A1 Pérez Lago, Laura A1 Viedma, Darío García de A1 Burillo Albizua, Almudena AB Centers for Disease Control and Prevention guidelines consider SARS-CoV-2 reinfection when sequential COVID-19 episodes occur >90 days apart. However, genomic diversity acquired over recent COVID-19 waves could mean previous infection provides insufficient cross-protection. We used genomic analysis to assess the percentage of early reinfections in a sample of 26 patients with 2 COVID-19 episodes separated by 20–45 days. Among sampled patients, 11 (42%) had reinfections involving different SARS-CoV-2 variants or subvariants. Another 4 cases were probable reinfections; 3 involved different strains from the same lineage or sublineage. Host genomic analysis confirmed the 2 sequential specimens belonged to the same patient. Among all reinfections, 36.4% involved non-Omicron, then Omicron lineages. Early reinfections showed no specific clinical patterns; 45% were among unvaccinated or incompletely vaccinated persons, 27% were among persons <18 years of age, and 64% of patients had no risk factors. Time between sequential positive SARS-CoV-2 PCRs to consider reinfection should be re-evaluated. PB GA Centers for Disease Control and Prevention SN 1080-6040 SN 1080-6059 YR 2023 FD 2023-05-02 LK https://hdl.handle.net/20.500.14352/130201 UL https://hdl.handle.net/20.500.14352/130201 LA eng NO Rodríguez-Grande, C., Estévez, A., Palomino-Cabrera, R., Molero-Salinas, A., Peñas-Utrilla, D., Herranz, M....de Viedma, D. (2023). Early SARS-CoV-2 Reinfections Involving the Same or Different Genomic Lineages, Spain. Emerging Infectious Diseases, 29(6), 1154-1161. https://doi.org/10.3201/eid2906.221696. NO La investigadora Almudena Burillo pertenece a Gregorio Marañón Microbiology-ID COVID 19 Study Group y realiza su aportación como autora colaboradora.Fondo Europeo de Desarrollo Regional (FEDER) – A way of making EuropeEuropean Centre for Disease Prevention and Control (ECDC) NO Instituto de Salud Carlos III NO Unión Europea NO Instituto de Investigación Sanitaria Gregorio Marañón DS Docta Complutense RD 19 ene 2026