Seroprevalence of Anti-SARS-CoV-2 IgG Antibodies in Healthcare Personnel in El Salvador Prior to Vaccination Campaigns oleh José Elías Aguilar Ramírez, Adrianna Maliga, Allison Stewart, Allison Lino, José Eduardo Oliva, Xochitl Sandoval, Emily Zielinski-Gutierrez, Rafael Chacon-Fuentes, Parminder S. Suchdev, Susana Zelaya, Mario Sánchez, Delmy Lisseth Recinos, Beatriz López, Ella Hawes, Julie Liu, Shannon E. Ronca, Sarah M. Gunter, Kristy O. Murray, Rhina Domínguez