Most American adults believe the vaccinations they received as a child are good for life, but it may be time for a vaccine booster. The reason we were taught vaccines were once and done is because of the theory of herd protection. Herd protection results when most people are vaccinated making it difficult for an infectious disease to find a host. In a herd environment the unvaccinated, or those whose vaccines are no longer sufficient for protection, are very unlikely to come in contact with an infected host.

The protective “herd” environment has been weakened in the United States. The contributors to the breakdown come from increased foreign travel, the anti-vaccine movement, and excess illegal immigration.
- There are no vaccination requirements for visitors to the United States. According to Our World in Data most of the developed countries have vaccination rates above 90%. However, many countries can only boost 80% vaccinations. A great many, such as Somalia and Ukraine are 50% or less.
- The robust anti-vaccine movement is active in the United states, but not isolated to the United States; it has affected many developed countries. In the report The Anti-vaccination Movement: A Regression in Modern Medicine reported that by 2003, the vaccination rate for measles had dropped as low as 61% in some parts of London.
- Illegal immigration at the southern border has exploded in recent years and participants are not isolated to Mexico with a 97% vaccination rate. Illegal immigrants have traveled to the southern United States border from all over the world. One example is the recent influx from the Congo, which only has a 69% vaccination rate. People travelling to the U.S> and overstaying their Visas also contributes to the illegal immigration issues.
This trifecta of potentially non-vaccinated population increases your risk of being exposed to an infectious disease, such as measles, mumps, and hepatitis. South Carolina is currently suffering statewide from a Hepatitis A outbreak. There have been numerous measles outbreaks across the United States in recent years, with 2019 being significant.

* Data are preliminary as of April 26, 2019.
US Department of Health and Human Services, CDC; 2019.
The headlines might seem far away and unrelated to your circumstance, but it’s probably still time for a visit to the doctor and find out if you are indeed protected by the vaccines you received as a child.
I was born in mid-west American in 1957 and was surprised when I found out my child-hood vaccination for measles, mumps and rubella (MMR) was no longer effective. According to the blood test if I were exposed to any of these diseases, I could catch them. I decided to get re-vaccinated. As a 62 year-old woman, I certainly don’t want to deal with the effects of measles or mumps. In the fall, I’ll get a shingles vaccination. Every ten years I get a tetanus vaccine. I feel I have enough other health issues to deal with that are not preventable, why should I invite more issues when I can prevent them with a vaccination? As an older adult, I encourage all older adults to check with their doctor and get assurance through a blood test that your child-hood vaccinations are still viable.
The CDC recommends several vaccinations for adults 19 and older. They also have an Adult Vaccine Assessment tool you can use and take the results to your doctor. If you use this tool, I highly recommend you choose the “factors that can increase your risk of hepatitis A or hepatitis B” answer if you frequently eat at restaurants. Restaurant workers contributed to the spread of hepatitis A in the South Carolina outbreak.


You may not be able to do anything to prevent arthritis or other health issues that come with being an older adult, but you can certainly prevent infectious diseases with vaccinations.