The world of Tzu Chi May 2020 (Vol.122)

eature The Covid-19 virus is raging across the globe, but a vaccine has yet to emerge despite the best efforts of numerous scientists working in research laboratories worldwide. In this article, virologist Assoc. Prof. Dr. Chee Hui Yee answers our questions on the prospects of a Covid-19 vaccine. No vaccine in sight? O n April 11, 2020, the World Health Organization (WHO) released a list of vaccines for SARS-CoV-2 (the virus that causes Covid-19) in various stages of development across the world, at least 70 of which are in the developmental phase, while three are undergoing clinical trials. But how do vaccines work? According to Assoc. Prof. Dr. Chee Hui Yee, virologist and academician at the Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, there are three ways for humans to defend against viruses: our immunity, vaccines and medical treatment. Viruses are like bacteria in that both contain genes, but genetic mutation occurs more frequently in viruses to ensure survival. In the process of replication, mutation changes the genetic sequence and is also likely to alter the protein molecules, rendering the virus foreign to the immune system. The immune system is unable to defend against the virus when it fails to recognize the virus protein. At this point, even vaccination is no longer effective. Dr. Chee cited the example of seasonal flu vaccines; the vaccines have to be administered yearly as different strains of influenza or flu viruses circulate, hence a new dose of a different type of vaccine is required to protect against each new strain of virus. Image source: Freepik.com 2020 • 05 08