The first work entitled "Differential risk for COVID-19 in the first wave of the disease among migrants from several areas of the world living in Spain", consists in a population-based cohort analysis of the cumulative incidence of PCR-confirmed COVID-19 among adult residents in Alcorcón (Spain) in the first wave of the disease through April 25, 2020. The article concludes that, lMigrants from sub-Saharan Africa, the Caribbean and Latin America, unlike Spaniards or migrants from Europe, North Africa or Asia, presented a higher risk of COVID-19. The data suggest a role for ethnicity in the risk of COVID-19. 

Reference: Pebble C, Pérez-Fernández E, González-Piñeiro B, Meléndez V, Goyanes MJ, Renilla ME, Casas ML, Sastre I, Velasco M.; COVID researchers Alcorcón (collaborators), Algora A, Alonso Punter JC, Bonilla Zafra G, Bueno-Campaña M, Castilla V, Díaz-Cuasante AI, Fabero A. Risk of COVID-19 in Spaniards and migrants from different parts of the world residing in Spain in the first wave of the disease [Differential risk for COVID-19 in the first wave of the disease among migrants from several areas of the world living in Spain]. Rev Clin Esp. 2020 Nov 20. Spanish. doi: 10.1016/j.rce.2020.10.006. Check the article here. 

The second work entitled "Impact of previous COVID-19 on immune response after a single dose of BNT162b2 SARS-CoV-2 vaccine", studies the immune response after a single dose of the BNT162b2 vaccine in people with previous SARS-CoV-2 infection. According to the research, the immune response increases markedly in these subjects, reaching IgG titers similar to those elicited by the two full doses in previously uninfected cases, and increases modestly after the second dose. These data can inform the need for the booster dose.

Reference: Velasco M., Galán MI, Casas ML, Pérez-Fernández E, Martínez-Ponce D, González-Piñeiro B, Castilla VI, Pebble C, Working Group Alcorcón COVID-19. Impact of previous COVID-19 on immune response after a single dose of BNT162b2 SARS-CoV-2 vaccine.doi:https://doi.org/10.1101/2021.03.08.21253065. Check the article here. 

Maria Velasco Arribas She is Associate Professor of the Department of Medical Specialties and Public Health of the URJC, and head of the Research Unit of the Fundación Alcorcón University Hospital (HUFA).

Carlos Guijarro Herraiz is Professor of the Department of Medical Specialties and Public Health of the URJC, and coordinator of research, teaching and innovation of the HUFA.