Let's start with the facts: any approved COVID-19 vaccine will be, for sure, safer than getting the disease. Vaccination remains a public good. I have told everyone I know they should be vaccinated, and I expect I'll have to argue my mother into it (WHY MOM, YOU ARE A LICENSED MEDICAL PROFESSIONAL). Also, you don't want to infect your nearest and dearest! That is not good!
However. If one more person tells me there's totally nothing to worry about and it's definitely 100% safe I will flip a goddamn table.
First go read this article on all the shady nonsense the FDA has pulled since March, including approving therapies that actually raise the death rate.
Then you can go read the entire Pfizer trial preliminary results (in two documents!).
First note that the median Phase 2/3 follow-up after the second dose is one month, for a total of two months. Yes. Two. When you hear people expressing concern over long-term effects- which there will be, there always are a few- don't bullshit them and say there's plenty of good long term data. There isn't. This is a novel technology not previously approved in humans. But you are less likely to die, or kill others, if you get vaccinated. There's your talking point.
Don't tell people that just because the FDA approved something, it's safe and effective. (See above, also, any time these last 100 years.) Say that this disease is deadly, and the trials are pretty large, and COVID definitely will kill you faster than two months.
When you hear people saying there were Bell's Palsy cases, that is true, and the incidence (over two months) was the same as the normal incidence over a year (though incidence varies widely by sex and age). Don't bullshit people and say it's totally within normal range. It may or may not be. Say that Bell's Palsy mostly resolves, and also, it will not kill you.
When you hear people saying there is insufficient safety data on people with previous infection, that is also true. The Pfizer trial gave 670 people (see p. 28) with serological evidence of previous infection their vaccine. Among these people, adverse events may or may not be more common. (Also, the US is about to do an accidental trial on all the medical personnel who were infected and didn't know it, so adverse events will show up there.) But also, please do not try to tell me, personally, that we know 100% for sure it's safe in people with previous infection. You can tell me that by the summer, we will have those data! We do not have the data now. But the vaccine still won't kill you.*
And also, there were at least two credible reports- in hospitals, in medical personnel! - of anaphylactic or anaphylactoid reactions (the latter can still kill you). The ingredients list is unconclusive as to what might have caused this- basically, PEG, the mRNA itself, or maybe one of the lipid components- but this is a legitimate reason to be concerned. Again, we do not have enough data now. For this one, I would say, don't dismiss the concerns of people with severe allergies; tell them to watch for more data.
So, overall: people are hesitant with good reasons. Some of these reasons can be addressed. By the time normal people can be vaccinated- in about six months- we will have enough data. But please don't tell people who legitimately want more data that everything's fine. That's how the FDA and CDC burned all that trust to start with.
* There will, eventually, be a fatal adverse event, which will be a one-in-ten-million event. On average, however, this will remain true.