If There Is No Disease, Why Are Some Vaccines Still Necessary?

There hasn’t been a single case of polio in the United States for decades. So why do we need to be immunized against it? While the United States has escaped polio for decades, other regions of the world have not been so lucky.

Travelers can unknowingly bring these diseases into the United States, and if the public is not protected by vaccinations, these diseases will quickly spread throughout the population causing epidemics.

Vaccinations are necessary to protect ourselves, even if we think our chances of getting any of these diseases are small. The diseases still exist and can still infect anyone who is not protected. A few years ago, in California, a child who had just entered school caught diphtheria and died. He was the only unvaccinated pupil in his class.

Another reason to get vaccinated is to protect those around us. There is a small number of people who cannot be vaccinated (because of severe allergies to vaccine components, for example), and a small percentage of people don't respond to vaccines. These people are susceptible to disease, and their only hope of protection is that people around them are immune and cannot pass disease along to them.

The CDC explains why, from a disease control and prevention perspective, parents should immunize their children:

Diseases are becoming rare due to vaccinations

It's true, some diseases (e.g., polio and diphtheria) are becoming very rare in the U.S. Of course, they are becoming rare largely because we have been vaccinating against them. But it is still reasonable to ask whether it's really worthwhile to keep vaccinating.

It is like bailing out a boat with a slow leak. When we started bailing, the boat was filled with water. But we have been bailing fast and hard, and now it is almost dry. We could say, “Good. The boat is dry now, so we can throw away the bucket and relax.” But the leak hasn't stopped. Before long we’d notice a little water seeping in, and soon it might be back up to the same level as when we started.

Keep immunizing until disease is eliminated

Unless we can “stop the leak” (i.e., eliminate the disease), it is important to keep immunizing. Even if there are only a few cases of disease today, if we take away the protection given by vaccination, more and more people will get infected and spread disease to others, and soon we will have undone the progress we made over the years.

Example case in Japan

In 1974, Japan had a successful pertussis (whopping cough) vaccination program, with nearly 80 percent of their children vaccinated. There were only 393 cases of pertussis that year in the entire country and no deaths. But then rumors began to spread that pertussis vaccination was no longer needed and that the vaccine was not safe. By 1976 only 10 percent of infants were getting vaccinated. In 1979 Japan suffered a major pertussis epidemic with more than 13,000 cases of whopping cough and 41 deaths. In 1981 the government began vaccinating with the acellular pertussis vaccine, and the number of pertussis cases dropped again.

What if we stopped vaccinating?

So what would happen if we stopped vaccinating here? Before long we would see epidemics of diseases that are nearly under control today. More children would get sick and more would die.

We vaccinate to protect our future

We don't vaccinate just to protect our children. We also vaccinate to protect our grandchildren and their grandchildren. With one disease—smallpox—we “stopped the leak” in the boat by eradicating the disease. Our children don't have to get smallpox shots any more because the disease no longer exists. If we keep vaccinating now, parents in the future might be able to look back at the “old days” when we had diseases like polio and measles for which children had to get vaccinated. 

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Important disclaimer: The information on is for educational purposes only and should not be considered to be medical advice. It is not meant to replace the advice of the physician who cares for your child. All medical advice and information should be considered to be incomplete without a physical exam, which is not possible without a visit to your doctor.

Immunizations stop
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