According to the British Association for the Advancement of Science, childhood diseases decreased 90% between 1850 and 1940, paralleling improved sanitation and hygienic practices, well before mandatory vaccination programs. Infectious disease deaths in the U.S. and England declined steadily by an average of about 80% during this century (measles mortality declined over 97%) prior to vaccinations.  In Great Britain, the polio epidemics peaked in 1950, and had declined 82% by the time the vaccine was introduced in 1956. Thus, at best, vaccinations can be credited with only a small percentage of the overall decline in disease related deaths this century.
Yet even this small portion is questionable, as the rate of decline remained virtually the same after vaccines were introduced. Furthermore, European countries that refused immunization for small pox and polio saw the epidemics end along with those countries that mandated it. (In fact, both small pox and polio immunization campaigns were followed initially by significant disease incidence increases; during smallpox vaccination campaigns, other infectious diseases continued their declines in the absence of vaccines. In England and Wales, smallpox disease and vaccination rates eventually declined simultaneously over a period of several decades.)
It is thus impossible to say whether or not vaccinations contributed to the continuing decline in disease death rates, or if the same forces which brought about the initial declines- improved sanitation, hygiene, improvements in diet, natural disease cycles- were simply unaffected by the vaccination programs. Underscoring this conclusion was a recent World Health Organization report which found that the disease and mortality rates in third world countries have no direct correlation with immunization procedures or medical treatment, but are closely related to the standard of hygiene and diet.  Credit given to vaccinations for our current disease incidence has simply been grossly exaggerated, if not outright misplaced.
Supporters of vaccination point to incidence statistics rather than mortality as proof of vaccine effectiveness. However, statisticians tell us that mortality statistics can be a better measure of incidence than the incidence figures themselves, for the simple reason that the quality of reporting and record-keeping is much higher on fatalities. For instance, a recent survey in New York City revealed that only 3.2% of pediatricians were actually reporting measles cases to the health department. In 1974, the CDC determined that there were 36 cases of measles in Georgia, while the Georgia State Surveillance System reported 660 cases. In 1982, Maryland state health officials blamed a whooping cough epidemic on a television program, D.RT.
- Vaccine Roulette,' which warned of the dangers of DPT; however, when former top virologist for the U.S. Division of Biological Standards, Dr .1. Anthony Morris, analyzed the 41 cases, only 5 were confirmed and all had been vaccinated.  Such instances as these demonstrate the fallacy of incidence figures, yet those who support vaccination tend to rely on them indiscriminately.
Vaccination Truth 3: It is unclear what impact vaccines had on the infectious disease declines that occurred throughout this century.