Vaccinations greatly reduced the prevalence of diseases and continues to be important for global health today. The low price of vaccines made them especially attractive as a way to improve global health and vaccines reached billions of people around the world.
# Empirical View
# The reduction of diseases after the introduction of vaccines
# The USA before and after the introduction of vaccines
People in richer countries continue to benefit from the application of vaccinations. But the benefits might possibly be forgotten just because the diseases have lost their threat after the introduction of the vaccines.
To see how we are benefiting from vaccinations it is necessary to compare the suffering before and after the introduction of the vaccine. This is what Roush and Murphy did for the US, and I have visualized the reduction in mortality for vaccine-preventable diseases in the following graph (and also reprinted a table with more results just below the graph). The graph shows that the reduction in mortality is mostly 100% across multiple vaccine-preventable diseases.
Reduction of cases and deaths of vaccine-preventable diseases in the United States after the introduction of the vaccine1
Reduction of number of cases for vaccine-preventable diseases in the United States before and after the introduction of the vaccine – Roush and Murphy (2007)2
|Disease||Number of Annual Prevaccine Cases||Number of Annual Postvaccine Cases||Reduction of Cases after Vaccine Introduction (in %)|
|Congenital rubella syndrome||152||1||99.30%|
|Acute hepatitis B||66,232||13,169||80.10%|
|Invasive (Haemophilus influenza type b)||20,000||<50||>99.8%|
|Invasive (pneumococcal disease)||63,067||41,550||34.10%|
Reduction of number of deaths for vaccine-preventable diseases in the United States before and after the introduction of the vaccine – Roush and Murphy (2007)3
|Disease||Number of Annual Prevaccine Deaths||Number of Annual Postvaccine Deaths||Reduction of Deaths after Vaccine Introduction (in %)|
|Congenital rubella syndrome||--||0||--|
|Acute hepatitis B||237||47||80.20%|
|Invasive (Haemophilus influenza type b)||–||<5||>99.5|
|Invasive (pneumococcal disease)||6500||4850||25.4|
# Decline of deaths from diarrhea after the introduction of the vaccine against the rotavirus in Mexico
The rotavirus is the most common cause of diarrhea and causes 527,000 childhood deaths annually (2011). Many more become sick and are hospitalized.4 Mexico introduced the rotavirus vaccination between 2006 and 2007, and the following graph shows how successful the countrywide vaccination was. According to the study, diarrhea mortality for children under the age of 5 fell by 56% over three years! The graph shows the seasonal pattern of the disease and how the lifesaving effect of the vaccine affected different age groups.
Number of diarrhea-related deaths among children 59 months of age or younger in Mexico by age group, July 2002 to December 2010 – Richardson, Parashar, and Patel (2011)5
# Measles – vaccination coverage and decline of measles
# Vaccination Coverage against Measles
The world map shows the share of children vaccinated against measles. In 1983 – the first year for which global data is available – only every second child was vaccinated against measles. In the latest data this share has increased to 84% globally.
# Increasing global coverage of vaccinations against measles
The following graph shows the increasing global coverage of measles-containing vaccine (MCV) and the simultaneous nine-fold reduction of the number of measles cases in our world. The measles vaccine was developed in 1963 and is extremely effective at preventing the disease6.
Measles global annual reported cases and MCV coverage, 1980-2009 – WHO7
# The global decline of measles
The following chart shows the number of reported cases of measles in the United States from 1980 to 2014. You can add more countries to the chart for comparison. The extremely large outbreak in 1990 in the United States was primarily caused by low vaccination coverage, and lead to a renewed push for vaccination and for the recommendation of a second dose in children. In 2008, there were 140 measles cases in the US, which was the highest annual total since 1996. These cases were caused by increased measles transmission due to unvaccinated children8. In 2014, 610 cases of measles were reported9. This recent increase in the number of measles cases demonstrates the importance of vaccination.
# Vaccination coverage
# Vaccination coverage against diphtheria, tetanus and pertussis
Up to date information on the global vaccination coverage is available at the Immunization Monitoring website of the WHO and the following graph, which shows the increasing immunization coverage against diphtheria, tetanus and pertussis.
The global effort is remarkable: In 1980 fewer than 1 billion were reached, today more than 6 billion people are reached. If you switch to the relative view we see that the share of the world population being vaccinated increased from 21% to 86%.
# Regional coverage against diphtheria, tetanus and pertussis
The below map shows the progress over time of DTP3 immunization coverage around the world. The most progress yet to be made is in Sub-Saharan Africa.
World maps of share of one-year-olds immunized with three doses of diphtheria tetanus toxoid and pertussis (DTP3)10
# Data Quality & Definition
Vaccines typically cause acquired immunity via some agent inside the vaccine that resembles the disease-causing microorganism. The agent can be made of killed or weakened forms of the microorganism, its toxins or its surface proteins. More information about vaccines in general can be found at the Wikipedia page on vaccines.
# Data Sources
# World Health Organization – Immunization surveillance, assessment and monitoring
- Data: Immunization coverage, system indicators and schedule, and disease incidence
- Geographical coverage: WHO member nations
- Time span: 1980-2014 for many countries
- Available at: Online here
- Data: Percent of one-year-olds immunized
- Geographical coverage: UN member nations
- Time span: 1980-2014 for many countries
- Available at: Online from UNICEF here. Also available via Gapminder here (search “vaccine” to find the data).