All licensed vaccines are extremely effective in preventing severe cases of Covid-19, a disease that has killed around three million people worldwide in the space of one year. However, there are still individuals who are more afraid of the vaccine than of the virus. The focus now is on the Oxford-AstraZeneca and Janssen vaccines, after dozens of those who were vaccinated Ââ about 1 in 100,000 â developed a very rare form of potentially lethal blood clots.
Below is a sample of risk-versus-benefit calculations. While approximate, they are useful for understanding the kind of figures used by drug regulatory agencies. We start by looking at a general scenario of 100,000 adults of all ages over a period of four months with an incidence of Covid-19 that reflects the rates experienced in 2021 in Spain: