Because this new vaccine is not a dead virus it should be safer. But as you state, it is new so there is the potential that side effects that were not observed during the trial will show up now that millions of people are receiving it.

Some side effects are good. Mild side effects such as injection site soreness and brief low fever indicate that the body is generating an immune response.

Some viral infections have long term consequences. Some are known to increase the risk of cancer later in life, HPV, epstein barr, and a few others. Some can have other nasty effects such as shingles for the chicken pox virus. There has even been some speculation that some forms of dementia may be related to prior viral infections (I think another herpes virus). We have already seen that some significant number of people have long term effects of fatigue, loss of smell, heart and breathing problems, and/or mental issues. I personally still have not fully recovered my sense of smell and feel like I struggle with tiredness and concentration more than before.

Now after saying all that, I would not be willing to force people to get the vaccine. But I do think we need to have more discussions about the options and consequences, both potential and known, so people can make the best decision possible for themselves.