NATIONALImmune system takes 14 to 21-days to respond to COVID-vaccineStaff WriterMarch 10, 2021 by Staff WriterMarch 10, 2021042 (UTV | COLOMBO) – Immune system take at least 14 to 21-days to respond to the COVID-vaccine, Professor Neelika Malavige of the Department of Immunology...