[Question] How dangerous is it to test a vaccine without animal trials?

I saw the idea a few times (in­clud­ing on LW), and sup­port it, to do/​al­low hu­man tri­als for Coron­aVirus vac­cine with­out an­i­mal tri­als.

My ques­tion is—how dan­ger­ous is it for a per­son to vol­un­teer to test a vac­cine (both with and with­out an­i­mal tri­als)?

How dan­ger­ous is it com­pared to get­ting the virus it­self?

How should some­one de­cide whether to vol­un­teer?