Here is an interesting article about making participation in experimental vaccine trials mandatory (Thanx and a tip o' the hat to Lew Rockwell).
[Nota bene: this is about participating in trials for experimental vaccines, not about mandating approved vaccines].
The general argument is that we need to develop new vaccines, and someone has to test them. Relying on people volunteering out of altruism is not working too well; the number of volunteers has been decreasing in recent years. The major alternative, paying them more than a pittance for their time, has two problems: (1) it preferentially causes the risks to be borne by "society’s most poor and vulnerable,: and (2) it creates "an inducement that inevitably clouds an individual’s appreciation of risk, limiting the likelihood that consent is informed."
Both arguments are poppycock. The worry about the "poor and indigent" is based upon the assumption that (a) the poor and indigent would be better off without this opportunity to make money and (b) equalizing burdens justifies what is, in essence, slavery.
The second argument, that too much of a financial inducement makes consent "uninformed" or that it "clouds" a person's judgment, ignores the issue of why doing such things is wrong: namely, because it tricks someone into making a decision that, if they were better informed or better able to appreciate the risks, they would not make. However, the proposed alternative is forcing someone to take risks that they would not take; it is hard to see how this is better. This is like claiming that having sex with a person who is too drunk to consent is unacceptable, because they might not consent to it if they were sober; but telling a sober person that they have to have sex with you and you don't care if they consent or not is more acceptable.
The only possible benefit to mandatory participation over payment is that you reduce the risk of participation fraud; that is, someone who does not qualify for the trial lying to get in and invalidating the results. But the article does not address this as a concern, and there must be ways of screening that will reduce that to negligible levels.
That is all.