Before being licensed and made available to the public, vaccines go through an extensive scientific and regulatory process to ensure their safety and efficacy. This includes clinical studies involving thousands of volunteers who are given the vaccine under investigation. This process does not stop after authorisation is granted, as vaccine safety data is continuously collected and scrutinised by health authorities.
Millions of people receive vaccines every year. Nothing in life is 100% safe nor 100% effective and vaccines are not completely free from side effects. The more common local reactions to an injected vaccine are redness and soreness at the vaccination site. There are only a few very rare serious side-effects among the millions of people vaccinated each year. It is the role of the public health decision makers in each country to ensure that the benefits that vaccination brings hugely outweigh any risks they may have.