Vaccination is arguably the most important medical intervention ever, not just because it protects the individual against infection but because if sufficient people are vaccinated it arrests the circulation of the infectious agent thus protecting those who were not or could not be vaccinated.
Without vaccination
* hundreds of thousands of people would still die each year from smallpox, even in rich countries
* infants would still die from diphtheria and whooping cough
* millions of children every year would suffer life changing paralysis caused by poliovirus
* up to a quarter of children catching measles would end up with hearing loss
* women would still be giving birth to infants with congenital rubella syndrome
* sexually active women would still run the risk of cervical carcinoma
* men who have sex with men would still run the risk of anal condylomata and cancer
* elderly people could still develop excruciatingly painful shingles
* children and teenagers would continue to die of meningitis
* elderly people would die more frequently from pneumonia, often slowly
* life expectancy at birth would fall back to levels seen 100 years ago
The list could go on and on. The only way to ensure that you didn’t run any risk of infectious disease and its consequences would be to live a life of total isolation from other people and certainly never to have sex. Bacteria develop resistance to antibiotics and antiviral therapy is still in its infancy and only really useful for HIV infection, hepatitis and Ebola. And when the next major influenza pandemic comes along with similar mortality rates to those seen in 1918-19 when more than 100 million people died, it will only be possible to check its course by vaccination.
As a viral epidemiologist I lecture on the science behind all this, but put simply vaccination is a no-brainer, unless of course you still believe in witch doctors rather than experienced scientists and doctors. Oh, one last point - the most recent research shows that measles infection destroys the immune memory of previous infections by other infectious diseases, thus rendering the individual susceptible to those diseases again.