Vaccines and Community Immunity: What You Need to Know
At FOMAT, vaccines and community immunity are areas where we have direct clinical trial experience, including our work during the COVID-19 pandemic. Community immunity is not just a public health concept for us — it is something we see play out in the diverse neighborhoods where our research sites are embedded. Educating our communities about the science behind vaccines and community immunity is part of how we build the trust that makes clinical research participation possible.
We share more than food and culture within our homes and communities. We can also spread disease. Luckily, we live in a time when vaccines can protect us from many of the most severe illnesses. Staying current on your shots helps you — and your neighbors — avoid getting and spreading disease.
How Vaccines Have Transformed Public Health
Vaccines have led to significant reductions in illness and death for both children and adults. One study estimated that among U.S. children born from 1994 to 2013, vaccines would prevent approximately 322 million illnesses, 21 million hospitalizations, and 732,000 deaths.
Vaccines harness your immune system’s natural ability to detect and destroy disease causing germs and then remember the best way to fight these germs in the future. Vaccination has completely eliminated naturally occurring smallpox worldwide — to the point that we no longer need shots against this fast spreading, deadly disease. Polio has been eliminated in the U.S. and most other nations as well, thanks to immunizations. Poliovirus can affect the brain and spinal cord, leaving people unable to move their arms or legs, or sometimes unable to breathe.
“These childhood diseases used to be dreaded problems that would kill or paralyze children,” said Dr. David M. Koelle, a vaccine expert at the University of Washington in Seattle. “In the 1950s, it was a common occurrence for kids to be fine in the spring, get polio over the summer, and then have to go back to school in the fall no longer able to walk.”
Why Vaccines and Community Immunity Work Together
Experts recommend that healthy children and teens receive shots against 16 diseases. With these shots, many disabling or life threatening illnesses have significantly declined in the U.S., including measles, rubella, and whooping cough. But unlike smallpox, these disease causing pathogens are still causing infections around the world.
“These days, the risks of not being vaccinated in a developed country like the United States may seem superficially safe because of low rates of infection due to vaccination and other advances in public health,” Koelle noted. “But we live in an era of international travel where we can be exposed to mobile pathogens.” Even if you do not travel, a neighbor or classmate could go overseas and bring the disease back to your area.
“When the rates of vaccination drop, there can be a resurgence of the disease,” explained Dr. Saad Omer, a global health researcher at Emory University in Atlanta. Measles was eliminated in the U.S. in 2000, but since then, thousands of cases have occurred, mostly related to travel and communities with lower vaccination rates.
When enough people are vaccinated, the entire community gains protection from the disease — this is vaccines and community immunity in action. It helps stop the spread of disease and protects the most vulnerable: newborns, the elderly, and people fighting severe illnesses like cancer.
“There’s a huge benefit to all of us getting the recommended vaccines,” said Dr. Martha Alexander-Miller, an immune system expert at Wake Forest Baptist Medical Center. “Number one, vaccines protect you. But they also limit the presence of disease causing entities circulating in the community. So you are helping to protect individuals who may not be capable of protecting themselves.”
Vaccines and Community Immunity During Pregnancy
When expectant mothers are vaccinated, immune protection can pass through the placenta to the fetus. “Early on, the baby’s immune system is immature. So there’s a period of vulnerability where disease and death can occur,” Omer explained. “But the mother’s antibodies — proteins formed by her immune system — can protect the baby.”
Doctors recommend that expectant mothers receive both flu and Tdap shots. A mother’s antibodies can help protect the newborn until they can receive their own vaccinations. Some vaccines must be given before pregnancy — rubella, for instance, can cause life altering congenital disabilities or miscarriage if contracted during pregnancy. The measles, mumps, and rubella vaccine provides prevention, and vaccines for many other common diseases that put newborns at risk are being actively studied.
The Future of Vaccine Research
“We’ve made amazing progress in the development of effective vaccines,” said Alexander-Miller. “Our ability to have such breakthroughs is the result of fundamental research that went on for years and years.”
NIH funded scientists continue to search for new ways to stimulate protection against various diseases. Some researchers are working to improve existing vaccines, as some require a series of shots to trigger a robust immune response, others can fade over time requiring booster shots, and some like the flu vaccine require annual updates because the virus changes each year.
Understanding how new vaccines are developed and tested requires understanding the clinical trial process. Our introduction to clinical trials explains how vaccine candidates move from early stage safety studies through Phase I to Phase IV trials before reaching the public.
For those interested in the broader role of personalized medicine in infectious disease prevention, our article on personalized medicine drug discovery explores how data driven approaches are shaping the future of therapeutic development.
According to the Centers for Disease Control and Prevention, vaccines and community immunity remain among the most cost effective public health interventions available — preventing millions of illnesses and deaths each year across the United States alone.
Most side effects of vaccines are mild, such as a sore arm, headache, or low grade fever. Ask your doctor whether your vaccinations are current and stay informed about new vaccines being studied and approved.