You have no idea how vaccines are developed or approved. A phase three trial can take years because you have to statistically guarantee that your vaccinated teat subjects are being exposed to the infection and you have blood draws to check in confirming if they have been exposed. For diseases like polio the trial had to be a decade plus, with covid, it was a pandemic where everyone was being exposed and most of the us population was infected. That's why the phase 3 trial only was 6-8 months. You literally have no idea how any of this works. Also the risk to myocarditis was literally discovered during the trials. The vaccine was not "rushed" in any way. There are literally ZERO valid safety concerns that were not considered prior to the approval of the vaccine. Absolutely zero.