There's hard data that the Covid-19 vaccines work remarkably well and prevent a lot of deaths and severe cases of Covid-19. Just one example:
ourworldindata.org/covid-deaths-by-vaccinationThe benefits of getting the shot (reduced risk of getting severely ill from SARS-CoV-2, i.e. pneumonia and necessary ICU care, and drastically reduced risk of dying from Covid-19) massively outweigh the minuscule risks of having an adverse effect (rare cases of myocarditis and even rarer cases of cerebral venous sinus thrombosis in some people).
These risks, albeit small, are transparently communicated to the public (in newspaper articles, publicly available data, scientific papers, pre-vaccination discussion with the doctor administering the vaccine, etc.). Medical doctors do whatever they can to further mitigate the risks (advise patients at a higher risk of experiencing an adverse effect like CVST, like young women, to get a vaccine different from the AstraZeneca vaccine for instance). The prevalence of adverse effects is publicly tracked and monitored by scientists (epidemiologists, virologists) and statisticians in several countries independently.
And all of this research shows that the Covid-19 vaccines have net positive impact.
Yet there are still people who think the vaccines are somehow more dangerous than the disease is. When in fact they are not, both adverse effects listed above are possible complications of the disease Covid-19 itself and occur at a much higher rate in the real disease.
How that's possible after three years of this pandemic is beyond me. Such ignorance has to be wilful at this point.
Disclaimer: Don't get health information from social media or lichess (including myself). Ask a doctor.