Sorry you are so wrong on this. The law is about reasonable people, by that I mean what a reasonable person would expect. That is why some acts by people while not having intent to harm but that do cause harm can be and are offences.
Manslaughter is the act of killing another person or person without intent to do so ie to murder someone requires intent but to kill someone and be charged with manslaughter requires no intent except that someone dies because of the actions of another were not reasonable. They may not be charged with Manslaughter but may be charged with Criminal damage or assualt depending on the circumstances. However accidental death is not an act that may be prosecuted, depending on how the death occurred as an example a child runs onto a road in such a manner that the driver of a car who was driving to the required and careful standards unavoidably hits and kills the child this would not be prosecuted but if the driver was speeding without lawful reason they would likely be charged and prosecuted with some offence.
I don't take away the right of choice but I also do uphold the right of consequences of those choices. One may choose to speed but if one does and are then caught doing so then they face the penalties/consequences of that choice. A person can choose to smoke cigars/cigarettes but if they do so and cause harm to another I support their right to sue the one who caused that harm. I even support the right of someone to refuse a vaccination but I also support the right of others to then take legal action that may include criminal proceedings if by that choice they harmed others, this is reasonable. What some people seek to do is assert their right to choices but they then don't want to be held to account for those choices.
Did I seek to ridicule? I don't think I did but if you felt that way I do apologise, I was responding to your post that noted prosecution was scary. For me the lack of care that some take in regards to others welfare is scary, I see it everyday with people speeding and breaking the rules on roads, improper handling of foodstuffs, lax safety standards, defective goods that endanger others and yes, those who refuse vaccinations because the disease it helps to protect against is of no real concern to the person refusing the vaccine.
I agree education is needed, particularly educating those who seek to avoid vaccination because they don't agree with it, that the reason to get vaccinated is not just about the person getting the vaccine but it is about helping to protect others. And sorry the jury is out on this matter otherwise we would still have major outbreaks worldwide of Smallpox, Polio, Tetanus, Whooping Cough, Measles and similar diseases that were and are reduced in threat by vaccines, it is just some refuse to accept the verdict. When hopefully a universal vaccine to Influenza is produced I am sure there would still be people who would refuse to get vaccinated for no other reason than that was their choice, but if by that choice they caused harm to another person then they should be held accountable for their choices.
And that doesn't make it about the welfare of humanity? Which then could be about national security and why the Governments of the World stockpiled Tamiflu etc during a previous outbreak to ensure the security of their nations was able to be maintained in the event of a catastrophic outbreak of a pandemic Flu. The rules were drawn up about who would be treated preferentially which included frontline health personnel, the Defence Forces, the Judiciary, The Political arm, and the Public Services. Health problems are of major concern to a nation's security and can be and are regulated, people are quarantined, people can be prosecuted.