Vaccines could do good if they “were safe” and didn’t have a trade off of death and adverse effects.
A lot of diseases have been eradicated by knowledge of where it comes from. Like sewer systems instead of dumping things in the streets and water ways like dead butchered animals that probably attracted rats too. I can imagine the smell of old European towns back when. Clean water, hand washing, regulation in food industry.
Others still around.
Suns good except in winter probably wouldn’t hurt to take supplements maybe not as high as 50K units but best to do your yearly tests in winter to see if you need them. As people get older too absorption by the sun might be inhibited too so good, so good to check. The doctor said mines good so far without supplements although I took a little bit not much being surrounded by the flu. It’s going from one person exposed to the next. At this point it will be a miracle if I don’t get it too.