Written by Kai-Ping Huang. To fight against Covid-19, there is only one solution for every country striving for a return to normality: vaccination. Herd immunity is the goal as advanced countries aim to vaccinate at least 75 per cent of their citizens. The discovery of different variants worldwide makes booster shots increasingly necessary to prevent severe symptoms even for the fully vaccinated. Although speed is vital, it is also essential to determine the proper order of vaccinations.
