Assessment of serum biomarker changes following the COVID-19 pandemic and vaccination: a cohort study in Sylhet, Bangladesh - Akther, Shangida; Samiha, Fairoz; Sony, Sabrina Amita; Haque, Mohammad Anamul; Hasnat, Mohammad Abul; Islam, S. M. Saiful; Ahmed, Shamim; Abdullah-Al-Shoeb, Mohammad (Frontiers in Public Health, 2025)