Vaccine Successes and Current Uses
A large body of rigorous science has clearly and repeatedly shown that vaccines in use today are exceedingly safe, with benefits greatly outweighing risks for individuals in groups recommended to get them. Contrary to widely disseminated misinformation about the purported dangers of vaccines, serious adverse health effects are very rare, while public health benefits are vast.
This article was published on
March 8, 2021
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Context and background
What diseases have been eradicated or significantly reduced by vaccines?
The following represent a few of the many diseases tackled by vaccines:
- In the 1970s, capping a decades-long international vaccination effort, smallpox became the first (and so far only) human disease to be eradicated from the planet.
- Polio afflicted more than 35,000 people per year on average during the late 1940s in the United States. With the introduction of polio vaccines beginning in the mid-1950s and subsequent and ongoing vaccination efforts, no cases of polio have originated in the United States since 1979, though the disease still exists in other countries. A global polio eradication campaign has been underway for many years.
- Each year between 1953 and 1963 in the United States, measles infected three million to four million people and killed 400 to 500—most of them children. The disease was declared eliminated (no disease transmission for at least 12 months) in the United States in 2000 after a concerted vaccination program, but U.S. outbreaks have begun to occur in communities where vaccination rates have dropped. Those outbreaks have been traced to cases originating through international travel.
- In 1921 alone, 206,000 documented cases of diphtheria in the United States led to 15,520 deaths. With routine childhood vaccination, the disease is now extremely rare in the United States, though it persists in some other countries.
- For the first 25 years that U.S. whooping cough (pertussis) case numbers were reported (1922-1947), there were between 100,000 and 300,000 cases every year. The number of people infected with whooping cough declined dramatically after the introduction of a vaccine. Nonetheless, more than 15,000 U.S. cases occurred in 2018—part of a recent increase that has been linked in part to inadequate vaccination rates but also to a switch in the 1990s to a new version of the vaccine that has benefits over the original but may not provide as long-lasting immunity as earlier versions.
What vaccines are currently given to children in the United States?
- There are currently 14 vaccines recommended for children by the U.S. Centers for Disease Control and Prevention (CDC), some of which are combination vaccines that prevent multiple diseases. Annual influenza vaccines are also recommended starting at the age of 6 months.
- Most vaccines routinely given to children in the United States are 85% to 95% effective in preventing disease in the vaccinated child. Evidence clearly shows that current vaccines for children approved by the Food and Drug Administration (FDA) are not only very effective but are very safe; notably, the myth that there is a link between vaccines and autism has been repeatedly disproved in scientific studies.
How widespread is vaccination in the United States?
- Vaccination rates vary by vaccine and age. The most recent National Immunization Survey—the annual assessment of vaccination coverage conducted by the CDC—examined three vaccines recommended in the United States and found that nearly 95% of U.S. kindergarteners had received each vaccine during the 2018-2019 school year. Nationally, 2.2% of kindergarteners had received exemptions from state vaccination requirements for at least one of the three vaccines due to philosophical or religious objections (“non-medical” or “personal-belief” exemptions, permitted in many states), while 0.3% were exempted from vaccination based on a medical condition that precludes vaccination.
- In the United States, more than 40,000 adults and about 300 children die annually from diseases that vaccines can prevent. From 2009 to 2018, 12 of the 18 states that allow parents to exempt their children from vaccination on the basis of religious or philosophical beliefs saw these exemptions rise, and more than a dozen metropolitan areas saw especially high numbers of exemptions (more than 400 kindergarteners each).
What happens when people delay or decline vaccination?
- Measles, an extremely contagious disease that is periodically brought into the United States as a result of international travel, provides an example: Among U.S. measles cases documented from 2000 to 2015 for which vaccination data are available, the vast majority occurred in unvaccinated people. More than 70% of the unvaccinated had an exemption based on religion or personal belief, rather than a medical exemption. In 2019 alone, there were 1,282 confirmed U.S. cases of measles—more than had been reported since 1992—71% occurring in unvaccinated people. About three-quarters of cases occurred in New York alone, a hotspot of non-medical exemptions from vaccinations.
- Vaccination rates are generally very high in the United States, but even local areas of lower coverage can lead to outbreaks. The percentage of the population that needs to be vaccinated to keep a disease at bay varies by disease; for some diseases, the U.S. Office of Disease Prevention and Health Promotion recommends vaccinating 90% of the population to prevent outbreaks. For measles, the World Health Organization recommends vaccinating 95% of the population, in part because it is so contagious.
- Many people without access to health care remain unvaccinated, and are made more vulnerable by those who, despite access, choose not to get vaccinated. Uninsured children have lower vaccination rates than insured children for most of the vaccines tracked by the National Immunization survey. By getting vaccinations, those with health care access help not just themselves but also others less able to receive vaccines.