As National Immunization Awareness Month, August is a great time to learn about vaccines and make sure all of your immunizations are up to date.
The Centers for Disease Control and Prevention recommends that children be vaccinated for 14 diseases during the first year or two of their lives (see the full recommended vaccine schedule here). Other vaccines are recommended for adolescents, adults and those considering international travel.
A Brief History of Vaccines Before vaccines were developed, outbreaks of infectious diseases that are now vaccine-preventable – like smallpox, diphtheria and measles – were fatal, especially for children. These diseases created widespread fear and panic, and killed a significant number of those infected. But those who survived developed immunity, and were unable to contract the disease again.
In the late 18th century, the English doctor Edward Jenner used cowpox to develop a vaccine which created immunity against smallpox, similar to the way surviving the disease created immunity. Over the next 200 years, effective and safe vaccines for several other infectious diseases were developed, significantly decreasing the occurrences of these diseases (see a full timeline of vaccine development here).
How do vaccines work? Vaccines are created using an inactivated or weakened version of the virus that causes the disease. This allows the immune system to prepare the defense it would need to protect the body from the infection-causing virus. Vaccines create immunity to the diseases they prevent, similar to the immunity developed from exposure to a disease. Even though many vaccines are developed using some version of the bacteria that causes the disease, you can’t contract the infection itself from the vaccine, making it safer than developing natural immunity (if you’re interested in a more in-depth assessment of how vaccines work, look here).
Benefits & Risks Vaccines have effectively reduced the number of cases of vaccine-preventable diseases by more than 90%, and for many diseases by more than 98%. Before the measles vaccine was discovered, there were more than 500,000 cases a year. In 2009, there were 71.
Vaccines don’t just protect individuals, either. If a large enough percentage of a group is immunized, the risk for any member of the group contracting the disease is reduced substantially. It’s called community immunity. If members of that group stop being vaccinated, instances of the disease increase significantly.
There are risks associated with vaccines, but the majority of them are minor (think a little bit of redness or soreness around the injection site or other minor discomforts). The risk of contracting a disease preventable by vaccine is usually much more significant than the risks of side effects. Prior to any vaccination, discuss the benefits and risks with your doctor or pharmacist.
The perceived risks of vaccines, more often than not, are the result of common misconceptions about where vaccines came from and how they work.
What Vaccinations Do I Need? The CDC produced a vaccination schedule for all to follow (the recommended schedule can be found here). Check with your doctor or pharmacist if you have any questions about your vaccination history or what vaccine requirements you have.