Our Immune system and the workings explained-by Dr Harold Gunatillake Effectiveness of the COVID vaccines -a challenge to our immune system Transcript: “In early May, two people quarantined in adjacent hotel rooms in the Australian city of Adelaide opened their doors within seconds of each other to collect meals. Health authorities believe that could have been enough for the virus to spread from a man in one of the hotel rooms to a man in the other via airborne transmission-. To combat such virulent contagious mutant variants, we need a strong immune system. Few weeks ago, the chief executive of Pfizer said anyone who receives its COVID-19 vaccine will probably need to have a third dose within 6-12 months after being fully immunised, and then likely one dose every year going forward. We will need these because it is likely that, for many of us, immunity will begin ...