Upvote:2
Based on the CDF's document regarding the Covid-19 vaccine, I would think that vaccine passports would only be permissible if:
Such a requirement is necessary to promoting the public good and
there are no possible legitimate objections a well-formed conscience could have to receiving the vaccine.
As it currently stands in regard to Covid-19, I do not know of any vaccines which satisfy 2, and I am personally of the opinion that Covid-19 is not a big enough threat to the common good to cause any vaccination to it to satisfy 1. The reason I believe these two conditions must be met is paragraph 5 from the linked document:
At the same time, practical reason makes evident that vaccination is not, as a rule, a moral obligation and that, therefore, it must be voluntary. In any case, from the ethical point of view, the morality of vaccination depends not only on the duty to protect one's own health, but also on the duty to pursue the common good. In the absence of other means to stop or even prevent the epidemic, the common good may recommend vaccination, especially to protect the weakest and most exposed. Those who, however, for reasons of conscience, refuse vaccines produced with cell lines from aborted fetuses, must do their utmost to avoid, by other prophylactic means and appropriate behavior, becoming vehicles for the transmission of the infectious agent. In particular, they must avoid any risk to the health of those who cannot be vaccinated for medical or other reasons, and who are the most vulnerable.
This paragraph makes clear that vaccination is a matter of conscience, with respect to Covid-19 specifically, because of the remote cooperation with the evil of abortion. Natural Law requires that our prudential decisions include the consideration of remote cooperation with evil. Also included in those considerations must be the outcome of our actions. If we can predict an action will have more evil effects than good, we can't take it, even if the act isn't intrinsically evil. So, if someone thinks, with good reason and sound judgement, that their participation in a particular regimen of vaccination will lead to more evil than good, they shouldn't be forced into taking that regimen. This is why I provided for requirement number two. A vaccine mandate/passport seems like it could only be ethical if no reasonable moral objections to the vaccine exist, otherwise someone may be forced to violate their conscience.