• Adult Immunizations
• Children's Immunizations
  • Why Immunize?
  • How Vaccines Work - What Is Immunity?
  • Immunity From Vaccines - How Vaccines Protect You
  • Why We Vaccinate - Purpose of Immunizations
  • 10 Vaccines Protect Us From 14 Diseases
  • Childhood Immunization Schedule
  • Disease Summary
  • Childrens Immunizations - Questions & Answers
  • Immunization Trivia
  • Immmunizations & Vaccine Glossary
• Flu Shot Clinics
• Pneumonia Immunizations
• Shingles Immunizations
• Travel Immunizations
• Allergy Testing
• Lab Testing
• Wellness Screening
• Education

Some childhood vaccines have been used since the 1940s, others have been around for only a short time. Currently there are 10 routinely used vaccines that protect children against the 14 diseases described in Part Two of this booklet. All of them have done an excellent job of reducing the burden of those diseases to their lowest point in history.

Because the diseases they prevent affect children, these vaccines are given during childhood. We will describe each vaccine, and then show the routine schedule for receiving all these vaccines. Contrary to a fairly common misperception, children have very robust immune systems, and can easily cope with multiple vaccines given on the same day.

Vaccine Side Effects

While vaccines are very safe, like any medicine they do sometimes cause reactions. Mostly, these are mild “local” reactions (soreness or redness where the shot is given) or a low-grade fever. They last a day or two and then go away. Sometimes more serious reactions are associated with vaccines. These are much less common. Some of them are clearly caused by the vaccine; some have been reported after vaccination but are so rare that it is impossible to tell if they were caused by the vaccine or would have happened anyway. We will mention side effects specifically associated with each vaccine in the descriptions below.

Some children also have allergies, and occasionally a child will have a severe allergy to a substance that is component of a vaccine. There is a very small risk (estimated at around one in a million) that a vaccine could trigger a severe reaction in a child who has such an allergy. Should one of these allergic reactions occur, it would usually happen within several minutes to several hours after the vaccination, and would be characterized by hives, difficulty breathing, paleness, weakness, hoarseness or wheezing, a rapid heart beat, and dizziness. Doctors’ offices are equipped to deal with these reactions. Always tell your provider if your child has any allergies that you know of.

Vaccine Precautions

A child who has had a severe (life-threatening) allergic reaction to a previous dose of any vaccine should not get another dose of that vaccine. A child with a known severe (life-threatening) allergy to any vaccine component should not get a vaccine containing that component.

If a child has any moderate or severe illness on the day any vaccine is scheduled, it should probably be delayed until the child has recovered. A mild illness or fever is usually not a reason to delay an immunization.

We will mention any additional precautions for each vaccine in the following descriptions.

0. DTaP Vaccine
0. Hepatitis A Vaccine
0. Hepatitis B Vaccine
0. Hib Vaccine
0. Influenza Vaccine
0. MMR Vaccine
0. Pneumococcal Vaccine
0. Polio Vaccine
0. Rotavirus Vaccine
0. Varicella Vaccine
0. Combination Vaccines

1. DTaP Vaccine

DTaP combines vaccines against three diseases, Diphtheria, Tetanus and Pertussis into one shot. (The small “a” in the name stands for “acellular,” which means that the pertussis component of the vaccine contains only parts of the pertussis bacterium rather than the whole cell.) The diphtheria and tetanus components of the vaccine are not technically vaccines, but “toxoids.” In other words, they help the immune system develop protection against the toxins produced by the diseases rather than against the disease bacteria themselves. All three components of DTaP are “inactivated” (killed). Tetanus, diphtheria and pertussis (DTP) vaccines have been in common use since the 1940s. DTaP vaccine (with the acellular pertussis component) was first licensed in 1991.

Children need five DTaP shots for maximum protection. The first three shots are given at 2, 4, and 6 months of age. The fourth (booster) shot is given between 15 and 18 months, and a fifth shot - another booster - is given when a child enters school, at 4-6 years. When it is given according to this schedule, DTaP protects most children from all three diseases (80%-85% from pertussis, 95% from diphtheria, nearly 100% from tetanus). Protection can fade with time, so booster doses (using Td or Tdap vaccine, see below) are recommended every 10 years. These vaccines are also sometimes given when a person gets a serious wound that could contain tetanus bacteria.

DTaP Vaccine Side Effects

Up to one third of children who get DTaP have local reactions (tenderness, pain, redness, swelling). These are most common after the 4th or 5th doses. When they occur it is usually within 2 days after the shot. Some children also experience swelling of the entire arm or leg after the 4th or 5th DTaP dose. This happens within 3 days of the shot and usually lasts around 4 days, with no after-effects. Up to about 1 child in 20 will get a fever of over 101°F - also more often after the fourth or fifth dose. And up to about 1 child in 5 may become fussy or lose their appetite for a day or two; nearly half may become drowsy after the shot.

More serious side effects include a fever of 104°F or higher (1 in 3,000), continuous crying for 3 hours or more (separate studies have found this in 1 in 900 to 1 in 8,000), and convulsions (1 in 14,000). Convulsions that occur after DTaP are usually not caused directly by the vaccine, but by a fever, which in turn was triggered by the vaccine. These are called “febrile seizures” and, while they might be alarming, children recover from them quickly and they do not cause permanent harm. Some experts recommend giving a non-aspirin pain reliever, such as acetaminophen, to reduce the chances of a fever.

Over the years several cases of permanent brain damage were reported following DTP vaccine (an earlier version of DTaP). Whether these were true vaccine reactions or merely coincidence is impossible to say, because they occurred so infrequently. Some people used to believe that DTP vaccine could cause Sudden Infant Death Syndrome (SIDS), but studies have discredited that theory.

DTaP Vaccine Precautions

In addition to the normal precautions for all vaccines, a child who developed encephalopathy (brain illness) within 7 days after a dose of DTaP should not get another dose of pertussis-containing vaccine (see DT vaccine, below).

There are several other conditions that might cause a doctor to recommend not getting DTaP. These are: a temperature of 105°F, a collapse or “shock-like” state, or continuous crying for 3 or more hours, occurring within 48 hours of a previous dose; or convulsions occurring within 3 days after a previous dose. If your child had any of these conditions after a previous dose of DTaP, be sure to talk with your doctor before getting another dose of the vaccine. He or she might recommend getting a non-pertussis-containing vaccine.

Other Related Vaccines

• DT is a tetanus/diphtheria vaccine, which does not contain pertussis. It is used for children younger than 7 years old who should not get pertussis vaccine (for example, because they have had a reaction to pertussis vaccine in the past).

• Td is similar to of DT, but is for children 7 years old and older and for adults. It has a lower concentration of diphtheria toxoid than DT. It is used for routine 10-year boosters.

• Tdap was licensed in 2005. It contains a full concentration of tetanus and lower concentrations of both diphtheria and pertussis. It is the first pertussis-containing vaccine licensed in the United States for older children, adolescents, and adults. It is currently recommended as a once-only booster for adolescents.

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2. Hepatitis A Vaccine

Hepatitis A vaccine is made from inactivated (killed) hepatitis A virus. It is 94%-100% effective in preventing hepatitis A. Because it has been available only since 1995, we don’t know yet how long immunity will last, but mathematical modeling suggests that it should protect for 20 years or more. The vaccine is not licensed for children younger than 1 year of age.

Until late 2005 hepatitis A vaccine was recommended only for certain children: those who live in states where risk of hepatitis A is highest and those who live in communities with high levels of hepatitis A, including Alaska Native villages, American Indian reservations, some Hispanic communities, and some religious communities. Travelers to countries where the disease is common should also get the vaccine.

As of 2005 hepatitis A vaccine has been routinely recommended for all children from 12 through 23 months of age.

Two doses of hepatitis A vaccine are recommended, the second dose given at least 6 months after the first. For travelers who don’t have time to get the second dose before their departure, one dose provides good short-term protection.

Hepatitis A Vaccine Side Effects

Mild local reactions, like pain or swelling where the shot is given, are reported in up to half of people who get the vaccine. Fatigue or mild fever are report less often-fewer than 1 person in 10. No serious reactions have been associated with the vaccine.

Hepatitis A Vaccine Precautions

In addition to the normal precautions for all vaccines, children who are known to have a severe allergy to alum should not get hepatitis A vaccine.

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3. Hepatitis B Vaccine

Hepatitis B vaccine is an inactivated (killed) vaccine that is made from a small, non-infectious part of the hepatitis B virus, called hepatitis B surface antigen. The vaccine was licensed in 1986, and 98%-100% of children who get the vaccine develop immunity.

Some parents question why infants and young children should be vaccinated against hepatitis B when they don’t have the risk factors (drug use, sexual activity, professional risk) that lead to many infections. There are two reasons. One is that babies and children can become infected too. If a mother infects her baby during birth, for example, and the baby is not immunized immediately, it will probably become chronically infected too. One out of 4 of these children will eventually die from cirrhosis or liver cancer. The other reason is that vaccinating only high-risk adolescents and adults has proved not to be a very effective way to control the disease. It was only after we began routine childhood vaccination that rates of disease began to drop significantly.

Three doses of hepatitis B vaccine are needed for full protection. The first dose is recommended at birth. This is particularly important for children whose mothers are chronically infected. The second dose is recommended at 1-4 months and the third at 6-18 months. These three doses should protect children for life. No additional booster doses are needed.

Hepatitis B Vaccine Side Effects

About 3-9 children out of 100 have some soreness where the shot is given, and up to 6 in 100 develop a mild fever. Up to 2 out of 10 might become tired or irritable. More serious reactions are extremely rare.

Hepatitis B Vaccine Precautions

In addition to the normal precautions for all vaccines, children who are known to have a severe allergy to yeast should not get hepatitis B vaccine.

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4. Hib Vaccine

There are several brands of Haemophilus influenzae type b (Hib) vaccine used in the United States. They are all inactivated (killed) vaccines, made from a only a small part of the Hib bacterium. All brands work equally well, protecting 95%-100% of children from Hib disease. The first Hib vaccine was licensed in 1985, and several improved versions have become available since then.

Children should get either 3 or 4 doses of Hib vaccine, depending on which brand your doctor uses. The vaccine is recommended at 2, 4, 6, and 12-15 months of age. The 6-month dose is not given with one brand of vaccine.

Hib Vaccine Side Effects

Hib is a very safe vaccine. It cannot cause Hib disease or meningitis, and is not known to cause any other serious reactions. About 2 children in every 100 who get Hib vaccine have redness, swelling or warmth where the shot was given, or a fever over 101°F. These reactions usually begin within 24 hours after the shot and last 2 or 3 days.

Hib Vaccine Precautions

In addition to the normal precautions for all vaccines, Hib vaccine should not be given to children younger than 6 weeks of age. This is not because it is unsafe but because it might not protect as well if given too early.

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5. Influenza Vaccine

There are two types of influenza vaccine. The first is an inactivated (killed) vaccine given as a shot, which has been used for many years. It can be given to anyone 6 months of age and older. The second is a live, attenuated (weakened) vaccine, which is sprayed into the nose and was licensed in 2003. It is not licensed for children younger than 2 years old.

Because influenza viruses change from year to year, new vaccines must also be formulated each year, and annual vaccination is recommended. The inactivated influenza vaccine is 70%-90% effective in healthy children, and the live, intranasal vaccine is about 87% effective in healthy children 5-7 years of age.

Many other infections have the same symptoms as influenza and are often mistakenly called “flu.” Neither vaccine is effective against infections that are not actually caused by influenza viruses.

One dose of vaccine (either type, depending on age) is recommended annually, beginning around October or November. For children younger than 9 who are getting influenza vaccine for the first time, 2 doses are recommended, and should be given at least a month apart.

Influenza Vaccine Side Effects

Inactivated Vaccine
About 15%-20% of those who get inactivated influenza vaccine have a mild local reaction, such as soreness or redness where the shot was given. These generally last 1 or 2 days. A very small number, less than 1%, may get a fever, chills or muscle aches. Because the virus in this vaccine has been killed, it cannot cause influenza.

Some inactivated influenza vaccine contains a preservative called thimerosal, which contains mercury. Some people believe that thimerosal in vaccines has been associated with developmental problems, including autism. In 2004 the Institute of Medicine reviewed scientific studies looking for a connection between thimerosal and these problems, but concluded that there is no evidence of such a connection. Parents can ask their providers about the availability of thimerosal-free vaccine.

Live, intranasal vaccine
Some children have gotten a runny nose or nasal congestion, fever, headaches or muscle aches, abdominal pain or vomiting. Since these symptoms are fairly common among all children, it is difficult to tell whether their occurrence after vaccination is due to the vaccine or not. Although the vaccine contains live influenza virus, it has been weakened and altered in other ways so it does not cause influenza.

Influenza Vaccine Precautions

Inactivated vaccine
In addition to the normal precautions for all vaccines, children who are known to have a severe allergy to eggs should not get inactivated influenza vaccine.

Live, Intranasal Vaccine
In addition to the normal precautions for all vaccines, children who have a severe allergy to eggs should not get live influenza vaccine. Children who have a weakened immune system, who have chronic medical conditions such as asthma, reactive airways disease, diabetes, renal disease, or sickle cell disease, or who are receiving long-term therapy with aspirin or other salicylates should also not get this vaccine. The vaccine is not known to be harmful to these people, but it has not yet been thoroughly tested in them.

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6. MMR Vaccine

MMR combines vaccines for Measles, Mumps and Rubella into one shot. MMR has been around since 1971, although its three components were licensed separately during the 1960s. It is a live vaccine, containing measles, mumps and rubella viruses that have been “attenuated” (weakened), so they won’t cause disease. Most children who get the vaccine develop immunity to all three diseases (over 99% for measles and 95% for mumps and rubella). Protection is believed to be life-long.

Two doses of vaccine are recommended, with the first dose given at 12-15 months of age. The second dose may be given 4 weeks after the first, but it is usually given at 4-6 years.

Measles, mumps and rubella vaccines may be given separately, although these individual vaccines are not always readily available. Doctors usually prefer not to give the vaccines this way because it means giving a child 3 shots instead of one.

MMR Vaccine Side Effects

Some children (about 1 in 5) get a mild rash or fever after MMR vaccine. These reactions begin a week or two after the vaccination and usually last for 1-3 days. About 1 child in 7 may get swollen lymph glands, and 1 child in 100 may have pain or stiffness in the joints that can last from a few days to a few weeks. There is a smaller risk of painful swelling of the joints (arthritis). These joint symptoms occur more often in adults, especially women.

Febrile seizures (seizures caused by a fever) have occasionally been reported after MMR vaccination. These usually happen 1 or 2 weeks after the shot and are caused by the fever than can accompany the vaccination rather than by the vaccine itself. Children recover from febrile seizures quickly and they do not cause permanent harm.

There have been reports of children getting encephalitis (inflammation of the brain) after an MMR shot. This happens so rarely - less than once in a million shots - that experts can’t be sure whether the vaccine is the cause or not. Remember, though, that if the same million children were infected with measles, about 1,000 of them would get encephalitis.

MMR Vaccine Precautions

In addition to the normal precautions for all vaccines, children who are known to have a severe allergy to gelatin or the antibiotic neomycin should not get MMR. A child who has a suppressed immune system, either because of a disease such as cancer or HIV infection or a medication such as steroids, should be evaluated by a doctor before getting MMR. A child who has recently gotten a transfusion or other blood product might have to wait up to several months before getting MMR.

Two live vaccines (for example, MMR and varicella) may be given on the same day or separated by at least 4 weeks. But they should not be given less than 4 weeks apart, because they might interfere with each other. MMR and inactivated (killed) vaccines may be given together, or at any time in relation to each other.

Children who have gotten MMR vaccine cannot infect people they come in contact with.

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7. Pneumococcal Vaccine

Pneumococcal conjugate vaccine was licensed in 2000. It is an inactivated (killed) vaccine, which gives immunity against the 7 strains of the pneumococcal bacterium that have caused most of the serious infections in children. It is more than 90% effective against invasive disease (for example, blood infections and meningitis). Some ear infections are prevented by pneumococcal vaccine, but many are caused by other organisms, and the vaccine will not prevent these.

Four doses of pneumococcal vaccine are recommended, at 2, 4, 6, and 12-15 months of age. Children who are late starting the series may need fewer doses. Check with your doctor or clinic for the recommended schedule if your child starts late. This vaccine is usually not given to children 5 years old and older. But some older children (those with certain chronic diseases or damaged immune systems) still need pneumococcal vaccine. There is a different vaccine - called pneumococcal polysaccharide vaccine - that can be given to these children and to adults. Pneumococcal vaccine may be given at the same time as other childhood vaccines.

Pneumococcal Vaccine Side Effects

Local reactions have been reported in 10%-20% of children getting the vaccine. Of these, only about 3% were considered severe (for example, tenderness that interferes with arm or leg movement). These local reactions occur most frequently after the 4th dose. Some children also report a mild fever. More severe reactions are extremely uncommon.

Pneumococcal Vaccine Precautions

In addition to the normal precautions for all vaccines, there are no precautions for pneumococcal vaccine.

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8. Polio Vaccine

The polio vaccine used in the United States contains 3 types of inactivated (killed) polio virus. It is sometimes called IPV (Inactivated Polio Vaccine). We once used another type of polio vaccine - a liquid that was swallowed, called OPV (Oral Polio Vaccine). This vaccine is no longer available in the United States but is still used in other parts of the world. The first inactivated polio vaccine (the Salk vaccine) was licensed in 1955, and the vaccine we use today (an improved version) has been in use since 1987. The vaccine protects 99% of children who get at least three doses.

Children should get four doses of polio vaccine, the first three doses at 2, 4, and 6-18 months of age, and a booster dose at 4-6 years.

Polio Vaccine Side Effects

Inactivated polio vaccine is a very safe vaccine. It is not known to produce any side effects other than a little soreness and redness where the shot is given. The old oral vaccine, OPV, could actually cause polio, although rarely. This cannot happen with IPV.

Polio Vaccine Precautions

In addition to the normal precautions for all vaccines, a child who is known to have a severe allergy to the antibiotics neomycin, streptomycin, or polymyxin B should not get polio vaccine.

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9. Rotavirus Vaccine

Rotavirus vaccine is a live vaccine, which is given orally rather than by injection. Children should get a total of three doses, one dose at 2, 4, and 6 months of age. The vaccine protects against five different strains of rotavirus, so even a child who has had a case of rotavirus disease should get the vaccine. The vaccine has been very effective in preventing rotavirus gastroenteritis (about 74%) and even more effective in preventing severe rotavirus gastroenteritis (about 98%).

Rotavirus Vaccine Side Effects

Children who get rotavirus vaccine have a slight risk of mild side effects, including mild, temporary vomiting, diarrhea, and earaches. No serious side effects have been associated with the vaccine.

In the late 1990s a different type of rotavirus vaccine was briefly available, but it was removed from the market because it was found to be associated with an uncommon type of bowel obstruction, called intussusception. The new vaccine was tested with more than 70,000 children before it was licensed, and millions of doses have been distributed since it was licensed. There is no sign that intussusception is a problem with this vaccine.

Rotavirus Vaccine Precautions

In addition to the normal precautions for all vaccines, a child who has a weakened immune system should be evaluated by a doctor before getting rotavirus vaccine. Suppression of the immune system can be caused by certain diseases such as cancer or HIV infection, or by medications such as steroids or chemotherapy. A child who has recently gotten a transfusion or other blood product might have to wait before getting rotavirus vaccine. Talk to your doctor if your child has any ongoing digestive problems or has ever had intussusception. Even though this vaccine hasn’t been associated with intussusception, children who had this condition in the past may be at higher risk of getting it again.

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10. Varicella Vaccine

Varicella vaccine is made with live, attenuated (weakened) varicella virus. It was licensed in the United States in 1995. It prevents chickenpox in 70%-90% of people who get it, and it prevents severe chickenpox in more than 95%. It is expected to provide life-long immunity. People who were vaccinated during testing, before the vaccine was licensed, are still immune.

Two doses of varicella vaccine are recommended for children. The first dose is recommended at 12-15 months of age. It is usually given at the same time as MMR vaccine. The second dose is recommended at 4-6 years, before entering kindergarten or first grade. It may be given sooner, as long as it is separated from the first dose by at least 3 months. Anyone who has had chickenpox does not need the vaccine.

Each year, about 1% of people who have gotten varicella vaccine develop chickenpox in spite of having responded to the vaccine. This is called “breakthrough” infection. Breakthrough infections are much milder than normal chickenpox. Patients generally have fewer than 50 lesions, which do not form blisters. They also do not get a fever and have no complications. We don’t know why breakthrough infections occur.

Varicella Vaccine Side Effects

About 1 child in 5 gets some redness or soreness where the shot was given. Some children also get a mild rash (about 5 spots) 1 to 3 weeks after the shot. About 15% of children get a fever, but most of these fevers have been shown to have causes other than the vaccine. Febrile seizures (seizures caused by fever) have occurred in less than 1 out of 1,000 children. Other serious problems, such as inflammation of the brain (encephalitis) or loss of muscle coordination, have been reported very rarely - so rarely that it is not certain that the vaccine is the cause.

Varicella Vaccine Precautions

In addition to the normal precautions for all vaccines, children who are known to have a severe allergy to gelatin or the antibiotic neomycin should not get varicella vaccine. A child who has a suppressed immune system, either because of a disease such as cancer or HIV infection, or a medication such as steroids, should be evaluated by a doctor before getting varicella vaccine. A child who has recently gotten a transfusion or other blood product might have to wait up to several months before getting varicella vaccine.

The manufacturer recommends not using aspirin or other salicylates for 6 weeks after varicella vaccine. This is because Reye syndrome has been associated with use of salicylates after chickenpox disease. Any similar risk associated with the vaccine is merely theoretical.

Two live vaccines (for example, varicella and MMR) may be given on the same day or separated by at least 4 weeks. But they should not be given less than 4 weeks apart, because they might interfere with each other. Varicella and inactivated (killed) vaccines may be given together, or at any time in relation to each other.

There is a very small risk that a child who has gotten varicella vaccine could infect a susceptible family member - particularly one with a suppressed immune system. This appears to happen very rarely, and only when the vaccinated child develops a rash. To be safe, anyone with a suppressed immune system should consider avoiding contact with a child who develops a varicella vaccine-related rash.

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Combination Vaccines

Several vaccines are sometimes combined into a single shot. These are called combination vaccines. Some combination vaccines are used routinely - DTaP is a combination; so is MMR. There are currently four other combination vaccines available for children. One combines DTaP and Hib vaccines; the second Hib and hepatitis B; the third combines DTaP, hepatitis B, and polio, and the fourth combines measles, mumps, rubella and varicella. The advantage of combination vaccines is, of course, that your children get the protection of all the component vaccines while getting fewer injections.

Each of these vaccines has certain restrictions, and not all providers carry them. But ask your provider about them if you are interested in reducing the number of shots your child needs.