It's not that simple
1) If you eliminate an orgnaism from an ecosystem, nearly always, something evovles to fit that niche'
and when delaing with pathogens a new one will usually be extremely nasty because it has not had time to adapt to the host
2) Smallpox was mega nasty, extreme mortality/communicability
It was NOT like polio, polio was mostly a public health issue as it basically spreads in contaminated water, ergo, clean place up and you do vastly more ot curb it than vaccines could ever do.
harm from polio infection was vastly lower than harm from smallpox (% chance)
yes, it put people in "Iron lungs" etc, but rememebr, more folk were getting torn into hamburger ont he road by a great deal. No one really gives a sh*t about road deaths as they are sacrifices ot the great Gods of Consumerism and Convenience.
Polio is NOT a "Plague"
3) Edward Henner never knew about things like Bovine Leukemia Virus
that is, vaccinatiosn have probably infected us with multiple pathogens which their creators didn't know about and couldn't detect.
odds are high that is how HIV really started.
Whether ME is caused BY a vaccine contaminant, or is merely triggered by any form of infection, the cluster outbreaks I'd bet are often linked to vaccinations
4) There are more Human beings....better media...better reporting...better research
So, more cases areproperly dientified rather than written off as "bug causes sickness" because no one knew
ie, today you get "over" reporting compared to the past
5) Packing more and more kids into bigger and oftne nastier maintained/built schools is ****** CRIMINALLY STUPID!!!
O M F G...schools are custom built germ labs, hence lice and other more obvious problems have sky rocketted.
6) Faster world travel
Air travel is behind huge amount of disease spread.
Joe B. escapes African civil war/poverty, comes to UK in forged papers, but is owned, controlled and slaved by scum Human traffickers
Joe B. has ebola...think the slavers will tell the rich pondslime he's working for peanuts for that he had Ebola?
Folks go on "adventure holidays" in rain forests, etc.
Normally such folk would recover or die off on ship voyages due to their long duration, but air travel is a recipe for disaster as it encloses folk together and is too short for vicitms to defeat the disease PLUS the slime air companies are breaking safety rules by using recirculated air, so, if Joe has some nasty bug YOU have the nasty bug
"bush meat" is traded across Europe despite the dangers of vast number of bugs and deaths that causes every year.
more obviously you have "Invasive" plant and other species causing havoc 'cause we Humans can't leave things the hell alone.
7) Said ages ago and indications are I was right, that virii play an important part in the evolution of higher organisms
This does not mean that slamming tons of virri AND vaccines into kids is a good idea, jeesh!!!
Every infection or injury has a risk of triggering very rare but catastrophic harm, and when you ge thit by many at the same time...the risks are nto merely simply additive.
8) We are designed to develope natural immunity, vaccines for many reasons do nor function liek natural infections/immune response, it's a gawd damn CON
Really, we're playing a huge game of "throw it all in the pot and stir and see what comes out!"

Vaccines should be *Banned*, except for those in high risk occupations and in specific cicumstances
for example, fertile females without contraception maybe wise to get rubella vaccination, especially if there's an outbreak.
A leatherworker who deals in foreign skins may seek anthrax shots
etc
You really wanna save lives, slam down hard on air travel, bush meat, human trafficking, slash school sizes/number in class rooms (ie set up massive building program so every kid has a school they can WALK to and no more than 250 kids in entire school)
ensure everyone has sufficent wage and encouragement to buy fresh food/fruit and live healthier lives.
Do more research, indepdendant research,into dangers form plastics and other environmental poisons, glass is in the end, safer than plastic bottles for kids ot drink out of (and we could make shatter proof glass too if we tried)
Sorry we're ALL going to DIE. Vaccines are a big boogieman to make you spend money and live in fear.
Kids will always suffer risk, they need ot unfortunately and paradoxically, to live healthy lives.
Dirt, injury and infection are natural and required for healthy life
More lives have been saved by public health and civil engineering than by vaccines, thing is, they do not make lots of money for the corporate bastards (and even then our scum governments have sold off water and other utilities, and see what that's done!).
Countries with crap or non existant water/sewer systems, public health programs etc wil lof course have sky high health issues.
Oen Is aw that highlighted the reality
in CHile iirc, they put in a big public water system, paid for by the IMF
know what? the IMF demaned that only those who could pay for the water should get it, the cost is 1/3rd the wage of the average lower clas person's annual income!
So there's all these big stopcocks, padlocked...
the wealthy fo course have water....and get diseases off the poor shmucks who drink polluted water even though they have fresh clean safe water right beside them...behind padlocks.
If you want ot look up other interesting things, note the number of youngsters who have died of horrible amoeba/fungal infections that get into the sinus/brain from swimming in water holes in US (in regard to polio)
number is small, death is horrific.
Do you make a vaccine for that, or ban/drain/clean the swimming hole?