Most vaccine side effects are mild. However, in some extreme cases, they can be life altering or fatal.
The HPV vaccine has been linked to increased fainting in girls. In studies, around 24 girls per 1,000 that received the vaccines would go on to faint later in life. Conversely, only around four in 1,000 that did not receive the vaccine had issues with fainting. The oral polio vaccine can, on rare occasions, cause paralytic polio. Some flu inoculations can cause Guillain-Barre syndrome, while others can lead to anaphylactic shock. These are all known and accepted side effects for vaccinations. Putting the benefits of the inoculation aside, it is impossible to argue that vaccines are “safe” when these are possible side effects.
90% of vaccine side effects are not serious and are limited to soreness and inflammation around the injection site. More serious side effects are exceptionally rare. There are fewer side effects of most vaccines than there are with paracetamol or acetaminophen.
[P1] Vaccines carry side effects that can be severe. [P2] Therefore, they are not safe.
[Rejecting P1] These side effects are exceptionally rare. [Rejecting P2] Vaccines are safer than paracetamol and acetaminophen, products we typically think of as "safe". Therefore, vaccines are "safe".