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Immunizations - InDepth

Highlights

Bacteria, viruses, parasites, and other germs (microbes) cause many human diseases. Vaccines can help protect against some of these diseases.

Data released recently shows that many immunization rates are below the Healthy People 2020 target rates. Vaccination (immunization) against infectious diseases saves millions of lives. Illness and death from diphtheria, pertussis, tetanus, measles, mumps, hepatitis, and other diseases can be prevented through immunization.

Introduction

Bacteria, viruses, parasites, and other germs (microbes) cause many human diseases. Vaccines can help protect against some of these diseases. Vaccination (immunization) against infectious diseases saves millions of lives. Illness and death from diphtheria, pertussis, tetanus, measles, mumps, hepatitis, and other diseases can be prevented through immunization.

Immunizations

Your body is designed to protect you from infections. When you are exposed to a virus, bacterium, or other microbe, your immune system actually "learns" from the experience. The next time your body is exposed to the same microbe, your immune system often recognizes it and sets out to destroy it.

During immunization, you are exposed to an inactive/weakened microbe or a very small and safe amount of part of a microbe. Your body's immune system responds to the vaccine by making substances called antibodies. If you are exposed to the microbe itself at a later time, the antibodies will kill the microbe and prevent infection or you may have a milder infection.

Most vaccines are given by an injection. Some can be taken orally (by mouth) or by a nasal spray. Vaccines contain one of four components that trigger an immune response:

Combination Vaccines

These are vaccines that combine more than one vaccine into a single injection (shot). Combination vaccines for diphtheria, tetanus, and pertussis (DTaP) and for measles, mumps, and rubella (MMR) have been available for many years.

New combinations that cover up to 5 vaccinations have been developed. They are safe and well-tolerated in infants as young as 2 months. For example, one such vaccine combines DTaP, hepatitis B, and the polio vaccines. It is as effective as the individual vaccines and is often used in order to minimize the number of injections (shots) given at one time.

Passive Immunity

Another form of protection against disease is called passive immunity. This approach uses immune globulin, which is a blood product containing antibodies. Immune globulin may be used for people who cannot be vaccinated, when immediate protection is required, or to prevent severe complications of the disease. In some cases, passive immunization interferes with active vaccinations, particularly live-virus vaccines. Therefore, these two immunization types are usually not administered within several weeks of each other. One exception to this rule is in the case of high risk exposure to rabies.

Each year the US Centers for Disease Control and Prevention (CDC) issues updated immunization schedules for children and adults. A schedule is a list of recommended vaccines and timing of their doses. The current schedules can be found at: cdc.gov/vaccines/schedules/index.html. This article describes routine vaccines for children and adults.

Routine Childhood Vaccines

In the US, many vaccines are first given during infancy. Even most premature infants can be immunized on a routine schedule.

Experts recommend that all children through 18 years of age be routinely vaccinated against the following diseases:

Common Adult Vaccines

Vaccines against the following diseases are recommended for adults:

Inactivated-virus and toxoid vaccines are generally safe in pregnant women. Tdap is safe and recommended for all pregnant women in their third trimester to boost immunity across the placenta to the baby after birth. Other vaccines should be delayed until the second or third trimester. Because of possible risk to the fetus, live-virus vaccines should not be given to pregnant women or women likely to become pregnant within 28 days. The exception is women who need immediate protection against life-threatening diseases, such as yellow fever, which can only be prevented with live-virus vaccines. The live-virus MMR combination, which vaccinates against measles, mumps, and rubella, is not given to pregnant women because of risk of the live-rubella vaccine to the fetus. The injectable inactivated influenza vaccine (preservative-free subtype) is safe to administer to pregnant mothers during the fall and winter months prior to start and during the influenza season.

Rubella Syndrome

Vaccines are not completely effective for people whose immune systems are compromised by disease or medications. Immune globulin is often given if there is a significant risk of infection. Live-virus vaccines are not usually given to people who have weakened immune systems due to illness or medication.

People who should not receive live-virus vaccines include:

Some people worry that vaccines are not safe and may be harmful, such as for children. They may ask their provider to wait or even choose not to have the vaccine. But the benefits of vaccines far outweigh their risks. For example:

Autism

Scientific studies have shown that vaccines and their components do not cause autism. Based on this evidence, the American Academy of Pediatrics, the Centers for Disease Control and Prevention, and the Institute of Medicine all conclude that the benefits of vaccines outweigh their risks.

Getting the Actual Infection From a Vaccine

Unless a person's immune system is weakened, it is highly unlikely that a vaccine will cause an infection. Some vaccines, such as the measles, mumps, rubella (MMR), the chickenpox, the rotavirus, and the nasal spray flu vaccines contain live but weakened viruses. These vaccines should not be given to people who have weakened immune systems.

Adverse Events

Like many medications, there is always a chance a vaccine can cause adverse events. An adverse event is a health problem caused by a medical treatment. An adverse event is also called a side effect.

No vaccine is 100% safe. Allergic reactions and other side effects may sometimes develop. In the US, the government and other agencies monitor side effects from vaccines:

Studies using these systems are ongoing and none to date have confirmed reports of any significant link between most vaccines and severe side effects that would outweigh their important benefits.

Infants often accept the first shot (injection) easily, since they are not expecting any pain or discomfort. It gets more difficult, though, with each additional shot. Providing reassurance can help children of all ages tolerate immunizations. Here are some tips:

If a person is ill with something more serious than a cold or develops a fever (if temperature is higher than 101°F [38.3 °C]), the vaccination may need to be scheduled for another day. Call your provider or immunization clinic for more information about this.

Severe Reactions to Vaccinations

Although severe reactions are very rare, you should know how to respond.

Call the provider right away if a child has any of the following symptoms.

Call 911 right away if a child has any of the following symptoms:

Call the provider if the following symptoms persist for more than 24 hours:

Adults who have any of the above side effects after vaccination should also seek medical attention.

After a severe reaction to a vaccine, such as an allergic reaction or convulsion, the person should not get any additional doses (shots) of the same vaccine. Call your provider or immunization clinic for more information about this.

Diphtheria, Tetanus, and Pertussis

Diphtheria

Diphtheria is caused by the toxin released by the bacterium Corynebacterium diphtheriae, which commonly infects the nose and throat. The throat infection leads to a gray to black, tough fiber-like membrane that can block the airway, making it hard to breathe, which can be life-threatening. In the early 1900s, diphtheria infected 200,000 people every year in the United States, killing up to 10% of infected people. Since a vaccine became available in the 1920s, there have been almost no cases of diphtheria in the United States.

Tetanus

Tetanus is a disease that causes severe muscular contractions and convulsions. It is caused by a powerful toxin secreted by the bacterium Clostridium tetani. People become infected by this dangerous bacterium through skin wounds. It is fatal in 15% to 40% of cases. Since widespread vaccination began in the late 1940s, new cases of tetanus have dropped by more than 95%.

Pertussis (whooping cough)

Pertussis was a very common childhood illness throughout the first half of the 20th century. It is caused by the bacterium Bordetella pertussis, which spreads easily from person to person. Pertussis causes uncontrollable, violent coughing attacks that can last for several weeks or months. In infants, it can cause permanent health problems and even death. Because of the vaccine, cases of whooping cough in the US reached an all-time low of 1,010 in 1976. The incidence has risen in recent years, with over 40,000 cases reported in 2012, and over 15,000 cases reported in 2018. The increase has occurred because immunity from the vaccine wears off by adolescence. Therefore, more cases develop in adolescents and adults as well as in infants younger than 2 months, who cannot receive the vaccine. For this reason, a booster dose has been added to the routine adult vaccination schedule.

DTaP

DTaP is the shortened name of the routine vaccine recommended for children through 6 years of age. DTaP is a combined vaccine made from inactivated (killed) bacteria or components that cause diphtheria, tetanus, and pertussis.

Children should get 5 doses (shots) of the vaccine. One dose should be received at the following ages:

DTaP can be given as an injection (shot) by itself, or it can be combined with other vaccines:

The advantage of a combined vaccine is that there are fewer shots. A provider can tell you if a combination vaccine is right for your child.

Tdap and Td

Because immunity to diphtheria, tetanus, and pertussis wears off, booster vaccinations are needed. Tdap and Td are used as booster vaccines:

People who should receive the Tdap or Td vaccines include:

Common side effects include:

Severe side effects include allergic reaction.

Measles, Mumps, and Rubella

Measles

Measles (rubeola) is one of the most contagious human infections. It is caused by a virus. Measles used to be a very common childhood disease. Most cases resolve without serious complications. Symptoms include fever, cough, runny nose, and rash that covers the whole body. In severe cases, measles can cause pneumonia, encephalitis (inflammation in the brain), or death. Risk of these severe complications is highest in the very young and very old. In pregnant women, measles increases the rates of miscarriage, low birth weight, and birth defects.

Measles on the back

About 3 to 4 million people used to get measles yearly in the United States before vaccination started, and there were thousands of cases of measles-caused encephalitis or death each year. Vaccination programs have drastically reduced the incidence of measles in the US. But measles outbreaks still occur, usually starting with international travelers and being spread among groups of people who decline immunizations or in areas where immunization levels have decreased. In 2019, 1282 cases of measles were reported in the US, the largest number of cases in a year since 1994, over 70% of which occurred in unvaccinated individuals. Vaccination rates have stagnated worldwide in recent years. Outbreaks in 2018 led to over 140,000 measles deaths, mostly among children under 5 years of age.

Mumps

Mumps is caused by a virus. The infection may cause no symptoms. If symptoms occur, they include fever, headache, sore throat, and parotitis, or painful swelling of one or both parotid salivary glands (located between the ear and jaw). In some cases, mumps affects the lining of the brain and spinal cord, although this is usually not permanently harmful. Swelling of the testicles occurs in some males who have reached puberty, although sterility is rare. Deafness in one ear occurs very rarely.

Rubella (German Measles)

Rubella is caused by a virus. The infection leads to a mild illness that includes a rash, enlarged lymph nodes, and sometimes a fever. If a pregnant woman is infected during her first trimester, her baby has an 80% chance of developing birth defects, including heart abnormalities, cataracts, deafness, and learning disabilities.

Cataract

Vaccination programs have dramatically reduced the number of mumps and rubella cases in the United States. Some adults are still susceptible, particularly immigrants who were not vaccinated in their birth countries.

Rubella on an infant's back

MMR

The measles, mumps, rubella vaccine is called MMR for short. It is a routine vaccine recommended for children through 6 years old. MMR is a combined vaccine made from live but very weak viruses that cause the three diseases.

Children should get 2 doses (shots) of the vaccine. One dose should be received at the following ages:

In addition, prior to traveling outside the US, infants younger than 12 months old should get an early dose of the MMR vaccine at age 6 to 11 months old. These children should subsequently follow the recommended schedule and get another dose at 12 to 15 months old and a final dose at 4 to 6 years old.

Adults born during or before 1956 in the United States are considered immune because they likely had the actual diseases during childhood.

Adults -- 18 years old, or who were born after 1956 -- should get at least one shot of the MMR vaccine if:

People who received inactivated types of measles or mumps vaccine in the 1960s or 1970s should be revaccinated with two doses of the live MMR vaccine.

The American Academy of Pediatrics recommends the MMR vaccine for HIV-infected children, teenagers, and young adults, except for those who are severely immunocompromised. The vaccine appears to be safe in HIV-infected children. Measles infection is very dangerous in this population.

Women who can get pregnant and who have not had the MMR vaccine in the past should have a blood test to see if they are immune. Being immune means, they have had the three diseases or the vaccine in the past and are now protected. If they are not immune, they should receive the MMR vaccine. Women should not get this vaccine if they are pregnant or planning to become pregnant within 4 weeks. The vaccine may harm the baby.

MMRV

The MMRV combines the MMR vaccine with the chickenpox (varicella) vaccine into a single vaccine. One dose (shot) of MMRV is given to children at the following ages:

The advantage of the MMRV vaccine is that the child gets one less shot. The disadvantage is a higher chance of developing a fever of 102°F (38.8°C) or higher and seizures than with getting the MMR and chickenpox vaccines separately. Talk with the provider about whether the MMRV vaccine is right for your child.

The MMRV vaccine is not given to people 13 years and older.

Common side effects include:

Chickenpox

Chickenpox is caused by the varicella-zoster virus. Chickenpox is one of the most contagious childhood diseases. Nearly every unvaccinated child becomes infected with it. Symptoms include itchy, fluid-filled blisters all over the body that burst and form crusts.

The infection rarely causes complications in healthy children. In severe cases, though, children need to be hospitalized for treatment.

Chickenpox - close-up

This is a close-up picture of chickenpox. Early chickenpox lesions consist of small red papules that quickly fill with a yellowish or straw-colored fluid to form small blisters (vesicles), as seen in this photograph. Later, these vesicles will rupture, forming shallow erosions that crust over and then ultimately heal.

Chickenpox, acute pneumonia - chest X-ray

This chest x-ray shows cloudiness throughout the lungs, caused by acute pneumonia following chickenpox. Pneumonia, as a complication of chickenpox, rarely occurs in children, but is more frequent in adults.

Chickenpox can be serious in adults and in people with compromised immune systems. It can lead to severe pneumonia, encephalitis (infection of the brain), or even death. In people who had chickenpox as children, the virus stays quiet (dormant) in the nerves of the body for the rest of a person's life. When the virus becomes active, it causes areas of painful blisters. This condition is called shingles.

Herpes zoster (shingles) on the back

This image depicts a classical pattern for shingles. The infection follows a nerve root from the spine, along a rib, to the front of the chest. The area innervated by the nerve is called a "dermatome".

VAR

The chickenpox (varicella) vaccine is called VAR for short. It is made from weakened chickenpox virus. After getting the vaccine, a person is protected from getting chickenpox. Or if a person does get chickenpox, the infection is usually mild. The vaccine can also prevent chickenpox or reduce its severity if it is used within 3 days, and possibly up to 5 days, after exposure to the infection.

VariZIG, a varicella-zoster immune globulin was approved in 2012 for high risk individuals exposed to the virus. High risk candidates include:

It is the only one of its kind available in the United States. Ideally, it is administered within 4 days of exposure, but may be given within 10 days.

Recommendations for Young Children

VAR is a routine vaccine recommended for children through 6 years old. Children should get 2 doses (shots) of the vaccine. One dose should be received at the following ages:

Recommendations for People 13 Years and Older:

Healthy adults without a known history of chickenpox, and who have had a blood test that does not show immunity, should receive 2 doses of the vaccine, including the following groups:

MMRV

MMRV combines the chickenpox vaccine with the measles, mumps, rubella (MMR) vaccine into a single vaccine. One dose (shot) of MMRV is given to children at the following ages:

The advantage of the MMRV vaccine is that the child gets one less shot. The disadvantage is a higher chance of developing a fever of 102°F (38.8°C) or higher and seizures than with getting the MMR and chickenpox vaccines separately. Talk with your provider about whether the MMRV vaccine is right for your child.

The MMRV vaccine is not given to people 13 years and older.

People who cannot be vaccinated, but are exposed to chickenpox, may receive immune globulin against the varicella virus. When received within 4 days of exposure, it may help reduce the symptoms of chickenpox.

Common side effects at the injection site include:

Sometimes a mild rash develops within a month of vaccination, which in very rare cases, may spread chickenpox to others. People who have recently been vaccinated should avoid close contact with anyone who might be susceptible to severe complications from chickenpox until the risk has passed.

Severe side effects include an allergic reaction.

For more information, see the in-depth report on shingles and chickenpox (Varicella-zoster virus).

Shingles

Shingles is an infection caused by the varicella-zoster virus. This is the same virus that causes chickenpox. After a person gets chickenpox, the virus stays inactive (dormant) in the body. Years later, if the virus becomes active, it can cause shingles.

Shingles is most common in adults over age 50. It causes a painful, red, and sometimes blistery rash to form on the body or face. Other symptoms include:

In rare cases, complications, such as pneumonia, blindness, and brain inflammation (encephalitis), can occur. In some people, after the rash goes away, the intense pain persists. This pain is called post-herpetic neuralgia (PHN).

The shingles (zoster) vaccine is recommended for healthy adults age 50 years or older, regardless of whether they have had shingles.

There are two shingles vaccines available in the United States:

Common side effects at the injection site include:

Some people experience headache or several days of shingles-like neuralgia symptoms.

Hepatitis A

Hepatitis A is a contagious disease caused by a virus that causes liver inflammation. The virus is excreted in feces and spreads when a person eats food or drinks water contaminated by the virus. Eating raw shellfish taken from sewage-contaminated water is a common means of contracting hepatitis A. It can also be acquired by close contact with people infected with the virus, such as in daycare centers.

Hepatitis A

HepA

The hepatitis A vaccine is called HepA for short. HepA is made from the inactivated virus.

Children should get 2 shots (doses) of HepA between 12 and 23 months old. The 2 shots should be separated by 6 to 18 months. Children 2 through 18 years old should get the 2 doses of HepA if they live in an area where many people have hepatitis A infection.

The vaccine can also be effective when given within 2 weeks of a known exposure.

Adults, 19 years and older, should get the 2 doses of HepA if they:

Hepatitis A Inactivated and Hepatitis B (Recombinant)

This vaccine combines the hepatitis A and hepatitis B vaccines into a single vaccine. The brand name of this vaccine is TWINRIX.

The most common side effects are:

The most serious side effect is an allergic reaction.

Hepatitis A immunization (vaccine)

Hepatitis B

Hepatitis B is a serious disease that causes life-threatening liver damage. Worldwide about 350 million people are infected with the hepatitis B virus. Each year 780,000 people die worldwide, mostly due to cirrhosis and liver cancer caused by long-term (chronic) hepatitis B infection. In the US, about 1.2 million people have chronic hepatitis B and up to 80,000 become newly infected each year.

Hepatitis B is also known as serum hepatitis. It spreads through blood and sexual contact. The infection is seen with increased frequency among intravenous drug users who share needles and among the homosexual population. The photo above is an electron microscopy image of hepatitis B virus particles. (Courtesy of the CDC.)

Hepatitis B spreads through blood and sexual contact. People at high risk of the disease include:

Pregnant women with hepatitis B can transmit the virus to their babies. Even if they are not infected at birth, unvaccinated children of infected mothers can get hepatitis B.

Hepatitis B infections have been greatly reduced since routine childhood immunization began in the early 1990s. But there are still children who are not immunized, and the disease persists. Routine vaccination against this disease during childhood is very important.

HepB

The hepatitis B vaccine is called HepB for short. HepB is made from the inactivated virus.

Hepatitis B

Recommendations for Childhood

HepB is a routine vaccine recommended for infants through 18 months old. Three doses (shots) of HepB should be received at the following ages:

Infants of mothers infected with hepatitis B should be treated with immune globulin plus HepB within 12 hours of birth. The second dose of HepB should be received at 1 to 2 months old and the third dose at 6 months old.

Infants born to infected mothers should be tested for antibody status at 9 to 18 months to see if they are long-term (chronic) virus carriers or need to be revaccinated.

When it is not known if a mother is infected, the infant should receive the vaccine within 12 hours of birth. The mother's blood should then be tested right away. If she is infected, the infant should receive immune globulin within 1 week of birth.

Hepatitis B Vaccine for Adults

HepB is received in 3 doses (shots) over 6 months. It is routinely recommended for all unvaccinated children aged less than 19 years. In addition, the following adult groups are at high risk and should be vaccinated:

Other people at risk who would benefit from vaccination include:

Hepatitis A Inactivated and Hepatitis B (Recombinant)

This vaccine combines the hepatitis B and hepatitis A vaccines into a single vaccine. The brand name of this vaccine is TWINRIX.

Your provider can tell you if this vaccine is right for your child or you.

DTaP-HepB-IPV

This vaccine combines HepB with two other vaccines: diphtheria, tetanus, pertussis (DTaP), and polio (IPV). It is for children 6 weeks through 6 years of age. Three doses (shots) are recommended at 2, 4, and 6 months of age. The advantage of this vaccine is that it reduces the number of injections a child has to receive. Talk with the provider about whether the DTaP-HepB-IPV vaccine is right for your child.

The most common side effects are fever or soreness at the injection site. The most serious side effect is an allergic reaction.

For more information, see the in-depth report on hepatitis.

Pneumococcal Disease

Pneumococcal disease is caused by the pneumococcus bacterium, Streptococcus pneumoniae (S pneumoniae). Different types of pneumococcal disease include respiratory infections, blood infections, ear infections, and meningitis. The most common type of severe pneumococcal disease is pneumonia.

People at highest risk of pneumococcal disease are:

Pneumococci organism

This photo shows the organism pneumococci. These bacteria are usually paired (diplococci) or appear in chains. Pneumococci are typically associated with pneumonia, but may cause infection in other organs, such as the brain (pneumococcal meningitis) and bloodstream (pneumococcal septicemia). (Courtesy of the CDC.)

PCV13

The pneumococcal conjugate vaccine protects against 13 of the most severe types (strains) of the over 90 strains of S pneumoniae. For this reason, this vaccine is called PCV13 for short. These 13 strains affect mainly children and about half of adults who get pneumococcal disease. PCV13 is made with components of the 13 S pneumoniae strains. The CDC recommends PCV13 vaccination for all children younger than 2 years, all adults older than 65 years, and people ages 2 to 64 years with certain medical conditions.

PCV13 is one of the recommended childhood immunizations. Children should get 4 doses (shots) of PCV13. One dose should be received at:

One dose of PCV13 and one dose of PPSV23 may be given to older children or adults with weakened immune systems due to health conditions such as HIV or kidney and spleen problems. People with cochlear implants may also need the vaccines.

PPSV23

The pneumococcal polysaccharide vaccine is called PPSV23 for short. It protects against the 23 strains of S pneumoniae that cause the most severe infections. PPSV23 is made from components of 23 S pneumoniae bacteria strains without extra protein. PPSV23 is not fully effective in people who are very old or have long-term (chronic) health problems.

PPSV23 is recommended for the following older children and adults:

Your provider can tell you about the timing of the PCV13 and PPSV23 vaccines.

Common side effects include:

Children are more likely to have fever within 48 hours if they receive other vaccines at the same time, and also after the second dose.

Poliomyelitis

Poliomyelitis is commonly known as polio. The disease is caused by a virus called poliovirus and can lead to paralyzing nerve damage, which can be fatal or lead to lifetime disability. Polio was a major killer of children in the early 20th century. Vaccination programs have eliminated the disease in most parts of the world. But cases still occur in certain parts of Asia and Africa. Vaccination is still recommended because there is still a risk of acquiring polio through international travel.

Poliomyelitis

Poliomyelitis is a communicable disease caused by viral infection and occurs through direct contact with infected secretions. Polio is found worldwide, but immunization has reduced the incidence. Clinical polio affects the central nervous system (brain and spinal cord). Disability is more common than death.

IPV

The polio vaccine is made from inactivated poliovirus. For this reason, the vaccine is called IPV for short. IPV is given as an injection. The oral polio vaccine is no longer used in the United States.

Polio vaccine is one of the recommended childhood immunizations. Children should get 1 dose (shot) of IPV at:

Children who have received 3 doses of the IPV before age 4 should get the fourth dose before or at the time they start school. The fourth dose is not needed if the third dose is received after age 4.

Combination Vaccines

The polio vaccine can be given as a shot by itself. Or it can be combined with another vaccine:

The advantage of a combined vaccine is that there are fewer shots. The provider can tell you if the combined vaccine is right for your child.

The most common side effects are soreness at the injection site or fever. Serious side effects may include an allergic reaction.

Influenza

Influenza is also known as the flu. It is caused by the influenza virus. The virus spreads easily from person to person. The flu causes a sore throat, fever and chills, headache, muscle ache, cough, and fatigue. Influenza is responsible for over 200,000 hospitalizations a year in the US and results in thousands of deaths.

Pneumonia is a major serious complication of the flu. It nearly always occurs in high-risk people such as the very young or very old and pregnant women. People who are hospitalized or whose immune systems are weakened are also at high risk of complications.

Influenza

Influenza, also known as the flu, is caused by a virus.

There are 3 types of the influenza virus that can infect humans:

Each influenza virus has different subtypes or strains. The seasonal flu vaccines work by protecting against those strains which experts think will be the most common for that season.

The flu vaccine is recommended for everyone 6 months and older.

However, it is most important for people at increased risk for complications from influenza infection, and for people who care for them. This includes:

For more information, see the in-depth report on colds and the flu.

The flu viruses are constantly changing their make-up. Scientists develop new vaccines each year to protect against the new flu strains that are expected to strike. The ability of the virus to change rapidly is why people need to receive a new vaccine each year.

People should get vaccinated each year before flu season starts. This is usually in September or October. One dose of the vaccine is needed. Children, 6 months through 8 years old, who are getting a flu vaccine for the first time need 2 doses.

The vaccine can be received as an injection (shot) or as a nasal spray. The injection can be delivered under the skin (intradermal) or into the muscle (intramuscular).

Injection

The flu shot contains killed (inactive) viruses. It is not possible to get the flu from this type of vaccine. Ahead of each flu season, the CDC makes the recommendation for the type of flu shot that will be recommended. Examples include:

Nasal Spray

Sometimes the seasonal flu vaccine recommendation includes a nasal spray option. The nasal spray flu vaccine is made from live, weakened viruses. It is approved for healthy people ages 2 through 49 years, who are not pregnant. There is no data that suggests the live virus in the nasal spray is any more effective. Depending on the circulating strains, this form of the vaccine may not be recommended. Talk to your provider to find out if the nasal spray is advised.

People who are severely ill or have a fever should reschedule their flu vaccinations for after they have recovered.

Injection

People who should not get the regular vaccine include:

Flucelvax and Flublok

People who should not get Flucelvax or Flublok include:

Nasal Spray

People who should not get the nasal spray include:

Possible side effects of the flu vaccines include:

Haemophilus influenzae Type B

Haemophilus influenzae (H influenzae) type b is a bacterium that commonly caused childhood bacterial meningitis, pneumonia, blood infection, and epiglottitis (throat swelling that can block breathing). Despite its name, this bacterium is entirely different from the viruses that cause influenza (the flu). Prior to the vaccine, about 600 children died of Hib infections every year in the US. Because of routine vaccination, serious Hib disease in children is now rare.

Haemophilus influenza organism

The photo above is a Gram stain of spinal fluid from a person with meningitis. The rod-like organisms seen in the fluid are H influenzae, one of the most common causes of childhood meningitis (prior to the widespread use of the H influenzae vaccine). The large red-colored objects are cells in the spinal fluid. A vaccine to prevent infection by H influenzae type b is available as one of the routine childhood immunizations (Hib), typically given at 2, 4, and 12 months.

Hib vaccine is highly effective in protecting against Hib disease. It is a routine vaccine recommended for children through 5 years old. Two vaccine brands are available. Depending on which vaccine is received, 3 or 4 doses (shots) are received.

Hib immunization (vaccine)

Hib can be given as a shot by itself, or it can be combined with another vaccine:

Your provider can tell you whether the combined vaccine is right for your child.

Adults with certain health problems, such as sickle cell disease, or conditions affecting the spleen, should have the Hib vaccine if they have not already been vaccinated. Hematopoietic stem cell transplant recipients should also receive a 3-dose regimen 6 to 12 months after transplantation, regardless of vaccination history.

Side effects of the Hib vaccines include:

Human Papillomavirus (HPV)

HPV is actually a group of more than 150 viruses, about 40 of which are sexually transmitted. Some HPV strains can cause genital warts, cervical cancer, and cancers of the vulva, vagina, anus, and penis. HPV infection is very common. About 20 million people in the US have it. At least half of all sexually active men and women will eventually be exposed to the virus.

The HPV vaccine is made from inactivated human papillomaviruses. The vaccines protect against HPV strains 16 and 18, which account for 70% of cervical cancer cases in the United States.

HPV9

HPV9 is also known by its brand name Gardasil-9. The vaccine protects against 9 types (strains) of HPV.

It is recommended for both males and females. It is routinely given at 11 or 12 years of age, but it may be given in beginning at age 9 years through age 26 years.

Current Immunization Guidelines Recommend

Girls ages 11 and 12 years should receive the HPV vaccine series:

Girls and women ages 15 to 26 years:

Boys ages 11 to 12 years should receive the Gardasil-9 vaccine series:

Boys and men ages 15 to 21 years:

Men ages 22 to 26 years:

Women and men ages 27 to 45 years:

The most common side effect of either vaccine is soreness at the injection site.

Meningococcal Disease

Meningococcal disease is caused by the meningococcal bacterium, Neisseria meningitidis (N meningitidis). The major, life-threatening meningococcal diseases are meningitis (infection of the lining of the brain and spinal cord) and septicemia (blood infection).

Meningococcus is spread when someone comes into contact with the respiratory and throat secretions of an infected person, such as through coughing or kissing.

Although just over 1,000 people a year get meningococcal disease in the United States, 10% to 15% of these people die. Of the people who survive, 11% to 19% have permanent health problems such as deafness and other nervous system problems.

People at highest risk of meningococcal disease include:

MCV4

The meningococcal conjugate vaccine is called MCV4 for short because it protects against 4 types (strains) of N meningitidis. The vaccine is made from portions of N meningitidis bacteria.

MCV4 is a routine vaccine recommended for adolescents, 11 through 18 years old. High risk children may be vaccinated at age 10. One dose (shot) should be received at:

One or more doses of the vaccine are also recommended in certain high risk children and adults, ages 9 months to 55 years old.

MenB

The meningococcal serogroup B recombinant vaccine is another available vaccine that specifically protects against the most common form of meningococcus found in outbreaks, serotype B.

This vaccine is recommended for adolescents, greater than age 10 through age 25 years in certain high risk scenarios. Two doses should be given at least 1 month apart.

MPSV4

Another meningococcal vaccine, called Menomune, is a polysaccharide vaccine. It is the only meningococcal vaccine for people over age 55 years.

The most common side effect is soreness at the injection site or mild fever.

Rotavirus

Rotavirus is a virus that is the most common cause of diarrhea, cramps, and vomiting in infants and toddlers worldwide. The virus is spread from person to person. Before the vaccine was developed, as many as 80% of young children in the United States came down with symptoms of rotavirus disease. Tens of thousands of children were hospitalized and 20 to 60 children died of the disease each year.

The rotavirus vaccine is made from weakened, live rotavirus. It is an oral vaccine. Rotavirus vaccine is one of the recommended childhood immunizations. Depending on the vaccine brand, 2 or 3 doses are received. One dose is received at:

Babies with the following conditions should not receive the vaccine:

Mild side effects that go away quickly include:

Serious side effects may include blocked intestine (rare).

Other Vaccines

Many other vaccines are available, including vaccines for:

These vaccines are not routinely given to the general population. They are only recommended to people who are at risk of exposure to the specific germ. For more information about these vaccines, visit the CDC website -- www.cdc.gov/vaccines/vpd/vaccines-diseases.html.

Rabies

Cutaneous anthrax

Tuberculosis of the lungs

Vaccines for Travelers to Developing Countries

People who are traveling to countries where certain infectious diseases are common should seek consultation in a travel clinic or check with the Centers for Disease Control and Prevention (www.cdc.gov/travel) for up-to-date information on immunization requirements for their destinations.

For more information, see the in-depth report on traveling to developing countries.

Resources

References

Bernstein HK, Kilinksy A, Orenstein WA. Immunization practices. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21th ed. Philadelphia, PA: Elsevier; 2020:chap 197.

Centers for Disease Control and Prevention website. Recommended immunization schedule for adults aged 19 years or older, United States, 2020. www.cdc.gov/vaccines/schedules/hcp/imz/adult.html. Updated February 3, 2020. Accessed May 20, 2020.

Centers for Disease Control and Prevention website. Recommended immunization schedule for children and adolescents aged 18 years or younger, United States, 2020. www.cdc.gov/vaccines/schedules/hcp/imz/child-adolescent.html. Updated February 3, 2020. Accessed May 20, 2020.

Dormitzer PR. Rotaviruses. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 150.

Freedman MS, Hunter P, Ault K, Kroger A. Advisory Committee on Immunization Practices Recommended Immunization Schedule for Adults Aged 19 Years or Older — United States, 2020. MMWR Morb Mortal Wkly Rep 2020;69:133–135. PMID: 32027627 pubmed.ncbi.nlm.nih.gov/32027627.

Freedman DO. Protection of travelers. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 318.

Kroger AT, Pickering LK, Mawle A, Hinman AR, Orenstein WA. Immunization. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 316.

Robinson CL, Bernstein H, Poehling K, Romero JR, Szilagyi P. Advisory Committee on Immunization Practices Recommended Immunization Schedule for Children and Adolescents Aged 18 Years or Younger — United States, 2020. MMWR Morb Mortal Wkly Rep 2020;69:130–132. PMID: 32027628 pubmed.ncbi.nlm.nih.gov/32027628.

Review Date: 6/14/2020
Reviewed By: Charles I. Schwartz MD, FAAP, Clinical Assistant Professor of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, General Pediatrician at PennCare for Kids, Phoenixville, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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