Historical comparisons of morbidity and mortality for vaccine-preventable diseases in the United States.
Level 4 - case-series / case-control
Historically controlled ecological surveillance study comparing pre- and post-vaccine era morbidity and mortality
PubMed 18000199 · doi:10.1001/jama.298.18.2155
What was done
Representative historical prevaccine baseline data from US primary sources were compared with recent morbidity (2006) and mortality (2004) data for 13 vaccine-preventable diseases with national recommendations established before 2005: diphtheria, pertussis, tetanus, poliomyelitis, measles, mumps, rubella (including congenital rubella syndrome), invasive Haemophilus influenzae type b (Hib), acute hepatitis B, hepatitis A, varicella, Streptococcus pneumoniae, and smallpox. Outcomes included numbers of cases, deaths, and hospitalizations, with percent reductions calculated without adjustment for confounding secular trends.
What was found
Diseases targeted by vaccines recommended before 1980 (diphtheria, mumps, pertussis, tetanus) showed a >92% decline in cases and a ≥99% decline in deaths. Smallpox was eradicated globally, while endemic transmission of poliovirus, measles, and rubella was eliminated in the United States. Diseases targeted since 1980 (hepatitis A, acute hepatitis B, Hib, varicella) achieved ≥80% declines in cases and deaths. Invasive S pneumoniae demonstrated smaller reductions, with a 34% decrease in cases and a 25% decrease in deaths.
Why it matters
This analysis establishes national benchmarks demonstrating the extensive population-level morbidity and mortality reductions associated with widespread vaccination programs in the United States.
Limits
The study used an unadjusted ecological before-and-after design that could not control for temporal confounders such as improvements in sanitation, nutrition, supportive medical care, or shifts in diagnostic and reporting practices. Total sample size and individual-level vaccination records were not reported in the abstract.
Cited by
- contradicts Ninety percent of measles was already gone when the vaccine was introduced, due to better sanitation and health.