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

eature Why is the process of developing a vaccine so time-consuming? The human immune system takes two weeks to produce adequate antibodies when the body is invaded by viruses. Some take longer, depending on the genetic makeup, which varies from individual to individual. This is why vaccine research takes a fairly long time. At the clinical research stage, a potential vaccine undergoes three phases of testing: Phase 1: The vaccine is administered on 20 to 30 volunteers, following which the researchers will conduct studies on the antibodies produced by the volunteers’ immune systems. This phase normally takes three to six months. Phase 2: The vaccine is administered on 500 to 600 volunteers. This phase, which takes more than eight months, focuses on analysing the dosage suitable for children, the elderly, pregnant women and other individuals with special conditions. Phase 3: The vaccine is administered on a large sample size – approximately 10,000 volunteers – across many communities and countries with different genetic makeup, which takes an even longer time. Ideally, a vaccine in development is expected to progress through the aforementioned phases, but often, the vaccine starts to cause adverse side effects or fails to produce the expected outcome in the second phase and is deemed unfit to proceed to the third phase. How is the development of a vaccine for the SARS-CoV-2 virus progressing? The genetic material present in virus is classified into DNA and RNA. The latter mutates easily. The SARS-CoV-2 virus discovered in Wuhan has mutated. Any vaccine developed to target the gene that had mutated is now ineffective. Scientists need to identify which gene has been more prone to mutation and which gene has been more stable within the past four months. A longer duration is needed for scientists to analyse the mutation rate of the virus and identify genes that are more stable. This is crucial to the development of medications and vaccines. Will our lives return to normal after a vaccine has been invented?Will we be able to attend social gatherings and dine at restaurants without wearing face masks? Once we have been vaccinated and the corresponding antibody is present, our bodies will be capable of defending against the virus and preventing us from falling ill. Everyone will be able to resume their lives as usual by then. Will vaccines cause side effects? All vaccines have to undergo stringent tests in order to fulfil safety standards. Only vaccines that are certified safe for use will be approved by the US Food and Drug Administration (FDA) and released to the market. Therefore, vaccines are safe. 2020 • 05 10