Immunizations for Babies

Immunizations are claimed to be one of the greatest success stories of the past century. Diseases that used to kill hundreds of thousands of children every year have been dramatically reduced to almost undetectable levels. There are numerous questions and concerns surrounding the topic of vaccinations. Should my child get immunizations? If so, when should they get them? Are they safe? Why do they have to have them?

I will start by providing an overview of vaccinations and how they work. We will then review each of the diseases protected against by the immunizations received during the first year of life. I encourage you to discuss any specific concerns or worries with your own health care provider. We are here as a resource for you and to help you sort thorough all of the contradicting and often confusing information that is available.

How Vaccines Work

Vaccines work by creating memory for the body’s immune system. Our immune system is a group of cells and chemicals that fight infection. When the body is exposed to a foreign bacteria or virus, the immune system starts to make something called “antibodies” that act as warriors to kill the foreign bacteria or virus. Most of the time this does not happen quickly enough and the bacteria or virus is able to make us sick. Once the immune system is able to generate enough antibodies that are able to kill off the foreign bacteria or virus, we “fight off” the illness and recover. Immunizations work to create a small “army” of these antibodies that are ready and waiting. When the body first sees the slightest sign of that particular bacteria or virus, it is ready and able to kill it off before any disease is caused. So, just by nature of how they work, vaccinations work to strengthen the immune system.


Potential Side effects
Immunizations are not without side effects. As with any medication given, there is potential for a reaction. The most common side effects seen after vaccinations are fever, fussiness, or fatigue. These may last for a day or two and fully resolve without any complications. There can also be a little redness or swelling at the injection site. More severe, but rare, reactions include a seizure or anaphylaxis reaction. For this reason, immunizations are always administered under medical care where oxygen and emergency medications are available. That being said, vaccinations are very safe and their proven benefits much outweigh the potential side effects.

What Vacccines Protect Against

There are twelve bacteria and viruses that we are able to provide protection from during the first year of life. They include Diptheria, Tetanus, Pertussis, Heomephilus influenzae, Polio, Pneumococcal, Rotavirus, Hepatitis B virus, Measles, Mumps, Rubella, and Varicella. Following, I will give a brief description of the diseases that each cause and the importance of providing protection from these infections.


Diphtheria is caused by bacteria that produce toxins in the body. These destroy and infect the tissues of our respiratory tract, including the nose, throat, and larynx. The swelling and exudate that form can obstruct the airway causing respiratory failure leading to death. It is treatable with antibiotics depending on the severity. In the 1920s there were close to 200,000 cases a year and 15,000 deaths reported each year in the United States. A vaccination against the bacteria became routinely used in the 1940s and only 5 cases have been reported since 2000. It does continue to occur in other parts of the world. The last major epidemic was in the former Soviet Union. The DTaP vaccine protects against this bacteria and is given during the first year of life at 2 months, 4 months, and 6 months of age.


Tetanus is caused by a bacteria that creates muscles spasms and whole body rigidity. The muscles of the jaw and neck can become very stiff. Seizures can occur. Spasms can continue for 3 – 4 weeks and complete recovery may take months. Death is caused by spasm of the muscles of respiration that interferes with breathing. The most fatal form is neonatal tetanus that occurs to infants whose mothers do not have protective immunity. There are still approximately 200,000 annual deaths worldwide, but this is very rare in the United States with only 2 cases of neonatal tetanus reported since 1989. Protection against tetanus has been available since the late 1940s. There are currently less than 100 cases of tetanus reported annually in the United States with an all-time low of 20 cases in 2003. The DTaP vaccine protects against this bacteria and is given during the first year of life at 2 months, 4 months, and 6 months of age.


Pertussis is also known as whooping cough. The bacteria that causes this infection leads cold like symptoms followed by coughing attacks. It has a common complication of pneumonia. Young infants are at highest risk to develop severe pneumonia and other complications such as seizures and brain damage. Prior to the vaccine, an average of 175,000 cases occurred per year. After the introduction of the vaccine, cases reached an all time low during the 1980s, with 2,900 cases reported annually. There has since been an increase with 25,827 cases reported in 2004. In 2005, 66 deaths from pertussis were reported in the United States and 85% of these were children under 3 months. It is felt that the immunity to pertussis wanes over a life time and that older kids and adults are getting sick with the pertussis bacteria, are only mildly ill because of healthy immune systems, and transmit the infection to newborns and infants. Because of this, a new booster shot is recommended after 10 years old. It is encouraged for you and all caregivers of your newborn to receive the Tdap immunization if they have not already. The DTaP vaccine protects infants against this bacteria and is given during the first year of life at 2 months, 4 months, and 6 months of age.


Polio is caused by a virus that infects the spinal cord causing paralysis. In addition, the poliovirus is highly contagious with nearly 100% of household contacts becoming infected after contact. The last case of paralytic polio was reported in the United States in 1999. It is possible that global polio eradication may be achieved within the next decade. The IPV vaccine protects against this virus and is given during the first year of life at 2 month, 4 months, and 6 months of age.


Haemophilus influenzae type b (Hib) is a cause of bacterial infections that are often severe, particularly among infants. Prior to the availability of the Hib immunization, this bacteria was the leading cause of bacterial meningitis among children. It causes several other infections as well, many of which are considered to be invasive disease, such as pneumonias, septic arthritis, epiglottitis, and cellulitis. These invasive infections most always required hospitalization and those that were not fatal, commonly had life-long complications such as hearing impairment. In the early 1980s, it was estimated that about 20,000 cases occurred annually in the United States. In 2005 there were less than 200 cases, and most of these were not of the invasive type. In March 2009 there was a Hib outbreak in Pennsylvania resulting in the death of three children. The Hib vaccine protects again this bacteria and is given during the first year of life at 2 months, 4 months, and 6 months of age.


Pneumococcal disease is caused by the bacteria Streptococcus pneumoniae. The most common infections include pneumonia, bacteria in the blood stream (bacteremia), and meningitis. More than 40,000 cases and 4,400 deaths from invasive disease (bacteremia and meningitis) are estimated to have occurred in the United Stats in 2005. The vaccine was licensed in 2000, and we are still continuing to see a decline in pneumococcal infections. The highest rates of invasive pneumococcal disease occur among children younger than 2 years old. The Prevnar vaccine protects against this bacteria and is give during the first year of life at 2 months, 4 months, and 6 months of age.


Rotavirus is a highly contagious virus causing severe diarrhea. It is most dangerous when the diarrhea leads to dehydration and infants are often hospitalized. Approximately 50 deaths occur annually in the United States attributable to rotavirus infection. The vaccine has been licensed since 2006 and is a liquid that is given by mouth at ages 2, 4, and 6 months old.


Hepatitis B is a virus that causes liver infection that can lead to liver damage chronic hepatitis. It is transmitted by blood contact or sexual contact. Because of this, most parents question why it is given soon after birth. It was not until the Hepatitis B vaccine was placed in the childhood immunization schedule that an actual decline and prevention of chronic liver disease and cirrhosis was achieved. This immunization, by nature of its immune properties, is very safe to give during the newborn period. It does not have the common side effects that other vaccines have, such as fever or fussiness. The Hepatitis B immunization is a 3 dose series with the first dose give prior to hospital discharge, the second dose at 1 – 2 months of age, and the third dose at 6 months of age.


Measles is a highly contagious viral infection that was nearly universal during childhood before a vaccine was available. It resulted in about 500 deaths annually and 30% of reported cases have one or more complications. The most serious complications include brain swelling and seizures, pneumonia, nerve damage, and exposure during pregnancy. Prior to licensure of vaccination in 1963 there were over 500,000 cases annually and in 2004 the lowest annual number of cases was 37. World wide 250,000 children die from this virus every year. The most recent outbreak in the United States began in California in early 2008 and spread to 15 states. The MMR vaccine protects against this virus and is given after your child’s first birthday.


Mumps is another viral infection that causes meningitis and hearing loss. It can also causes orchitis (testicular inflammation) in males which rarely leads to sterility. Deafness occurs in 1 per 20,000 cases, but hearing loss on only side is associated in 80% of cases. Following vaccine licensure the number of annual cases in the United Stats fell from 212,000 to 258 reported in 2004. There was an outbreak in 2006 resulting in 6,000 reported cases. Most were in older adolescents and young adults. The MMR vaccine protects against this virus and is given after your child’s first birthday.


Rubella is a virus that causes a rash, fatigue, and other nonspecific symptoms. The greatest benefit of vaccination is the prevention of transmission during pregnancy. If a baby is exposed to the rubella virus in the womb, there is a high chance of Congenital Rubella Syndrome. Early exposure is the most dangerous, with 85% of infants exposed in the first trimester being affected. Defects are rare when infection occurs after the 20th week of gestation. Infection may lead to fetal death, spontaneous abortion, premature delivery, deafness, eye defects, heart defects, and/or neurologic damage. Since 1980, approximately 5 cases of Congenital Rubella Syndrome are reported annually in the Unites States. The MMR vaccine protects against this virus and is given after your child’s first birthday.


Varicella is the infection more commonly know as chickenpox caused by the varicella zoster virus. This vaccine has been used in the United States since March of 1995. Prior to this, virtually all persons acquired chickenpox prior to adulthood. It is a common childhood illness that is highly contagious and causes a specific rash and fever. It is not without complications, however, and 11,000 people required hospitalized each year and approximately 100 deaths were reported annually. Secondary bacterial infections are the most common complications leading to blood stream infections. Pneumonia and central nervous system complications also occur.

Autism Contrversy

No overview of immunizations would be complete without mentioning autism. Over the past ten years, news stories have caused some parents to fear that the combination measles-mumps-rubella (MMR) vaccine causes autism. Although we still have a lot to learn about what does cause autism and how to treat it, we do have a wealth of knowledge that disproves cause by the MMR vaccine. The initial concern was raised in 1998 by a study published in London of a very small number of children. Those researchers have since retracted their statement acknowledging they did not have sufficient data to make that claim. Other critics claim that thimerosal, a preservative used in immunizations, is harmful to children because it is a mercury derivative. First, there are no studies that show that mercury at the level contained in vaccines was ever harmful or causes neurological problems. In 1999, thimerosal was removed from all of the vaccines that are routinely given to children in the United States and the rates of autism have continued to rise.


Because of vaccines, there are many devastating illnesses that we do not have to worry about our children catching. Until these illnesses are fully eradicated globally, immunizations remain critical to protect our children and ourselves. There is such a wealth of information on this subject, it is hard to cover everything in one article. I hope that I have answered some of your questions about why immunizations are so important and offered reassurance that they are safe. If you have specific questions or concerns, I encourage you to discuss them with your pediatrician or healthcare provider and hope they will be open to listening to your questions and concerns.

The Centers for Disease Control publishes a recommended schedule of what vaccines a child should receive and at what age. Here are copies of the schedules by age group:

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