Insights into COVID-19 Delta variant (B.1.617.2)


  • Angel Yun-Kuan Thye Monash University Malaysia
  • Ke-Yan Loo Monash University Malaysia
  • Kyle Bond Chene Tan Northern Ireland Centre for Stratified Medicine
  • Jenny May-Sim Lau Queen’s University Belfast
  • Vengadesh Letchumanan Monash University Malaysia



Since beginning of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), different variants of concern (VOC) have been discovered. One of the variants that stood out was the Delta variant (B.1.617.2), first found in India. It caught worldwide attention due to its greater transmissibility than the progenitor strain and the first variant of concern (VOC)- Alpha variant (B.1.1.7). B.1.617.2 spread rapidly across the globe and became a VOC due to its high transmissibility, clinical implications, and impact on vaccine efficacy. This review discusses the background and prevalence of B.1.617.2 and its sensitivity to convalescent sera and vaccinated individuals. We will provide an insight into the impact B.1.617.2 has on vaccine efficacy and discuss the level and type of protection an individual could get by being vaccinated. We will also discuss briefly on the COVID-19 vaccine booster doses and whether it is needed.






Review Articles