flu shots----Do you get them?

 My husband wants us both to get a shot. He's had them with no apparent side-effects, but I don't trust them. Think they're risky. I know people who've been very sick after getting a shot. You don't know what ingredients are in there, & where they come from. After countless numbers of people get the shots, then comes the info that maybe the formula wasn't the 'right one' for whatever strain is out there, & they come up with another type of shot. What gives here? Are we guinea pigs?