Before the development of the vaccine, measles infections resulted in thousands of hospitalizations and hundreds of deaths in the United States each year. After the vaccine became available, the number of cases dropped dramatically. While the number of infections remains low, measles has recently gotten into the news due to an outbreak in Washington (the state).
As of this writing, the number of people infected is low—but measles is exceptionally contagious. While those who have been vaccinated have an excellent defense against the disease, the unvaccinated are quite vulnerable. These people include those too young to get the vaccine and those who have medical reasons for not getting it. It also includes people who have elected to not have themselves or their children vaccinated. Washington allows citizens to opt out of vaccination, which is the reason that the population did not reach the percentage of people needed to provide herd immunity (that is, so many people are vaccinated, even the unvaccinated are protected because the disease will be limited in its ability to spread).
While medical reasons are clearly legitimate reasons to not get vaccinated, some states allow people to refuse vaccination based on their religious beliefs. Some states also allow an exception for “philosophical beliefs” about vaccines. While the legality is a matter for the lawmakers, this is clearly also an ethical matter.
Proponents of vaccine choice might argue that vaccines are harmful and hence it is the right choice to opt out, regardless of whether one is motivated by religion or philosophy. However, the measles vaccine (like almost all vaccines) is very safe. This is not to say that vaccination is without risk—they can have serious side effects. However, the risk of the harms prevented by vaccines greatly outweighs the risk of the vaccines. Also, most worries about vaccines are based on utterly debunked claims. To use an analogy, the argument against getting vaccinated is like the old argument about not wearing a seatbelt. One version of the seatbelt argument is that since a person could be trapped in a burning wreck, they should not wear their seatbelt because they will be safer. While there is some tiny risk in wearing a seatbelt, the risk of injury and death resulting from not wearing one is far greater—hence wearing a seatbelt is the good choice. Likewise, for vaccines. As such, except for people who are allergic to a vaccine or would otherwise really suffer medical harm, the argument that people should opt out because of the danger has no merit.
Religious and “philosophical” reasons to opt out of vaccines need not be based on harm or even on any appeal to facts. Even it the religious or “philosophical” claim could be shown to be false or even impossible, the justification would remain—after all these justifications are about what the person thinks, not about what is true. The basic idea is that the justification to opt out would be the person’s claim that their religion or belief forbids them from getting vaccinated or having their children vaccinated. As such, the justification would fall under freedom of religion/belief.
While my commitment to the freedom of belief entails that I think it is generally wrong to compel people to violate their beliefs, I accept the obvious fact that freedoms are not limitless. To use an absurd example, if someone believed sincerely in Cthulhu and wanted to sacrifice people to their imaginary god, this should not be allowed—freedom of religion does not grant a right to murder. This does point to a non-absurd point, namely that the freedom of belief does not grant a freedom to harm others.
To use an analogy, freedom of belief can be seen as like the freedom to drink alcohol. A person is free to drink as much as they wish, even if doing so is harmful to themselves or a bad live choice. However, this does not grant then the freedom to get behind the wheel while drunk. Likewise, for freedom of belief: a person can believe whatever crazy, false or wicked thing they wish as long as that belief is not used to try to justify harming others. While this principle applies obviously to human sacrifice, it also applies to vaccines.
While a person might argue that they are only putting themselves at risk when they elect to not have their child vaccinated, this is obviously not true. They are putting their child and others at risk. To use an analogy, they would be like parents who claim that the right to drink not only allows them the right to get drunk, but to go out for a drive with their kids. This would obviously put their kids and other people at risk—without their consent. As such, refusing to vaccinate one’s children when the vaccines have been proven safe and the risk of disease is real is morally unacceptable, no mater the beliefs of the parents. Beliefs about beer and drunk driving would not warrant exceptions to forbidding drunk driving, likewise beliefs about vaccines and disease would not warrant exceptions to vaccination.
It might be objected that adults should have the choice in their own case. In the case of vaccinations against diseases that do not spread (like shingles), there is no moral reason to forbid people from opting out—they are only putting themselves at risk. But, going back to the drunk driving analogy, it would obviously be wrong for a drunk adult to go driving even if they had no kids or left them at home. Naturally, if a person or group is willing to isolate themselves and have no contact with anyone else, then they would be free to vaccinate or not—this would be analogous to people agreeing to drive drunk together on private roads. It would be a stupid idea, but as long as everyone provides informed consent, then it would be morally acceptable. Of course, this would still not justify opting out on vaccinations for children—they cannot provide informed consent and accept the risk.
Based on the above arguments, allowing people to opt out of vaccines based on beliefs is immoral and should not be permitted.