Why does my child require so many vaccines? Can such a high number of vaccines weaken immune systems?

Author Name
Answered by: Kathryn, An Expert in the Vaccinations and Prevention Category
It can seem like children are required to receive an unusually high number of vaccines. The Center for Disease Control (CDC) recommends a total of eleven vaccines (each with two or more dose) before children reach the age of six. Further vaccines are suggested up through the age of 24. These vaccines protect against everything from the chickenpox to polio to diphtheria, but concerns have been raised in recent years that such a high number of vaccines weaken immune systems, especially in young children.

Some of these vaccines might also seem unnecessary. Polio, for example – once a national scourge that crippled thousands of children annually – is no longer found in the United States.


Despite appearances, however, this number of vaccines is actually quite safe. In their everyday life, infants are exposed to literally thousands of bacteria and viruses; their immune system, in turn, is capable of responding to a nearly infinite variety of microbes. A study by immunologists Dr. Mel Cohn and Dr. Rodney Langman estimated that children can respond to up to 100,000 unique organisms at any given time. Compared to what they’re exposed to naturally, the diseases children are introduced to via vaccine are merely a blip on the radar and cannot overwhelm the immune system.

It is interesting to note, as well, that although the number of vaccines has increased, the number of infectious particles within vaccines themselves have decreased. In the past, the smallpox vaccine contained 200 different viral proteins. Today, thanks to increasing vaccine effectiveness, the number of viral proteins children are exposed to remains under 130. Even though children are receiving more shots, their immune systems have less infectious material to fight off.

Neither can vaccines weaken immune systems. Vaccines are composed of viral proteins, not the viruses themselves, or viruses that are dead or so severely weakened as to cause no harm. While the immune system will mount a response–necessary to ensure future protection – the vaccines have been weakened so significantly that they leave the individual unharmed.

It’s also crucial that many of these vaccines be received at a young age. Although it might seem unlikely for a child to catch a disease such as hepatitis B, which usually affects young adults, many carriers of the disease live with the virus for years without showing any symptoms and can unknowingly pass it on to a child. Early vaccination is crucial for long-term prevention.

Vaccination also remains necessary for seemingly eradicated diseases such as polio. While no naturally-occurring cases are found today in the United Sates, the disease is still endemic in other countries around the world, meaning people traveling to those countries can bring it back with them.

While this number of vaccines can result in a high number of shots – an experience unpleasant for both parent and child – efforts have been made in recent years to combine doses, reducing the number of shots required for a child. This is an ongoing area of research and the number of shots required will hopefully continue to drop.

Author Name Like My Writing? Hire Me to Write For You!

Related Questions