This is the human face of smallpox:
Smallpox is now extinct in the wild: the last known case was in 1977.
And this is what Judy Wilyman has to say about the vaccine that eradicated smallpox virus, in her strongly anti-vaccine PhD thesis – you'll find the quote on page 15 of the main document:
Vaccination as a preventative public health strategy was first used by Edward Jenner in the late 18th century (Hays 2000). It was used in the fight against smallpox for ~150 years but its efficacy was never tested in controlled clinical trials that exposed a large number of participants to the smallpox virus and compared the outcome to a control group (Wallace 1898).
The disease killed an estimated 400,000 Europeans annually during the closing years of the 18th century (including five reigning monarchs), and was responsible for a third of all blindness. Of those infected, 20-60 percent – and over 80 percent of infected children – died from the disease.
The fact that developing countries are still rife with infectious diseases today suggests that depending on vaccines to prevent disease in countries with poor environmental and nutritional conditions is questionable