> Measles mortality fell markedly (>90%) from the 19th century to mid-20th century prior to introduction of measles vaccine or the widespread use of antibiotics for secondary bacterial infections [1][2]

This story is similar for most infections we now vaccinate for, death rates were dropping dramatically years before vaccines were introduced.

[1] https://www.cambridge.org/core/journals/epidemiology-and-inf... [2] https://scholar.google.com/scholar_lookup?title=Measles+mort...

The flu isn't a stable thing though, there are multiple strains of what we call "the flu" and its constantly adapting/mutating. Previous infection is no guarantee of protection, just like previous vaccination us no guarantee.

> When is this natural immunity supposed to kick in and stop the elderly and infirm from dying from it?

That's a whole different ball game. You're talking about immunocompromised individuals, their immune system isn't well prepared to respond to natural infection PR vaccination. Vaccines can still help, though they're usually less effective and more likely to cause symptoms similar to the original disease you're vaccinating against.

A vaccine isn't a magic bullet for preventing death. Vaccines still depend on the immune system doing its job effectively.

Vaccines attempt to induce natural immunity not reinforce it. This is precisely why vaccines are less effective for those with preexisting conditions and immune disorders - their immune system can't as easily respond to and learn from the vaccine. An effective vaccine stimulates the immune system after introducing enough material similar to the natural pathogen that the immune system can learn to respond to it. I could just be misunderstanding your meaning hear, but "reinforce" sounds to me more like an additional layer of defence - a beam reinforcing a homes foundation is adds additional strength to existing beams rather than making the existing beams themselves stronger.

I'm not arguing that we kill anyone. You're implying that choosing not to intervene with vaccines is murder, which I would disagree with, but even then I left open the door for that cost to not be worth it.

My argument here was simply that if vaccines aren't used, as happened for effectively all of natural history, the population remaining (assuming some remain) is stronger for it.

That doesn't meant we should choose not to administer vaccines if we have them and they are proven safe and effective. That also does not mean that we should actively kill anyone, eugenics is a pretty messed up idea.

> Measles mortality fell markedly (>90%) from the 19th century to mid-20th century prior to introduction of measles vaccine or the widespread use of antibiotics for secondary bacterial infections [1][2] This story is similar for most infections we now vaccinate for, death rates were dropping dramatically years before vaccines were introduced.

[1] https://www.cambridge.org/core/journals/epidemiology-and-inf... [2] https://scholar.google.com/scholar_lookup?title=Measles+mort...

What would make it murder?

I wouldn't propose that people should be stopped from taking a vaccine if they want it.

I'm a strong supporter of informed consent. In this context that simply means that people need to know the pros and cons of a vaccine, what isn't known or scientifically studied yet, and they can make their own mind up.