Infant flu shot

The flu shot or influenza vaccine is safe for pregnant women and provides effective protection for you and your newborn baby for the first six months of their life.

Seasonal influenza shots protect against the three or four influenza viruses that research indicates will be most common during the season. The flu shot is especially important for people with some medical conditions like kidney disease, diabetes, HIV, heart problems, or asthma to get a flu vaccine. These people are more likely to have serious health problems (like pneumonia) when they get the flu.

Kids and teens who take aspirin regularly also need to be vaccinated. They’re at risk for getting a serious condition called Reye syndrome if they get the flu.

Another reason to get vaccinated is to protect the people around you who might get very ill from flu — like babies, people with serious medical conditions, and the elderly. When you protect yourself with the flu vaccine, you also protect other people who are at risk because there’s less chance you’ll get the flu and pass it on. Sometimes people call this “herd immunity.”

The Centers for Disease Control and Prevention (CDC) recommends that everyone 6 months of age and older get a seasonal flu vaccine each year by the end of October ¹⁾. However, as long as flu viruses are circulating, vaccination should continue throughout flu season, even in January or later.

Special vaccination instructions for children aged 6 months through 8 years of age

• Some children 6 months through 8 years of age require two doses of flu vaccine for adequate protection from flu. Children in this age group getting vaccinated for the first time, and those who have only previously gotten one dose of vaccine, should get two doses of vaccine this season—spaced at least 4 weeks apart. Your child’s health care provider can tell you if your child needs two doses.
• If your child needs the two doses, begin the process early. This will ensure that your child is protected before influenza starts circulating in your community.
• Be sure to get your child a second dose if he or she needs one. It usually takes about two weeks after the second dose for protection to begin.

According to the CDC influenza is more dangerous than the common cold for children. Each year, millions of children get sick with seasonal flu; thousands of children are hospitalized, and some children die from flu. Children commonly need medical care because of flu, especially children younger than 5 years old.

Complications from flu among children in this age group can include:

• Pneumonia: an illness where the lungs get infected and inflamed
• Dehydration: when a child’s body loses too much water and salts, often because fluid losses are greater than from fluid intake)
• Worsening of long-term medical problems like heart disease or asthma
• Brain dysfunction such as encephalopathy
• Sinus problems and ear infections
• In rare cases, flu complications can lead to death.

Flu seasons vary in severity, however every year children are at risk. The CDC estimates that since 2010, flu-related hospitalizations among children younger than 5 years old have ranged from 7,000 to 26,000 in the United States ²⁾. While relatively rare, some children die from flu each year. Since 2004-2005, flu-related deaths in children reported to CDC during regular flu seasons have ranged from 37 to 187 deaths. Even though the reported number of deaths during the 2017-2018 flu season was 187, CDC’s mathematical models that account for the underreporting of flu-related deaths in children estimate the actual number was closer to 600.

Flu vaccines are updated each season as needed to protect against the influenza viruses that research indicates will be most common during the upcoming season. The 2019-2020 influenza vaccine has been updated from last season’s flu vaccine to better match circulating viruses. Immunity from the flu vaccination sets in after about two weeks.

Which children are at especially high risk of serious flu-related complications?

Children at greatest risk of serious flu-related complications include the following:

1. Children younger than 6 months old: These children are too young to be vaccinated. The best way to protect these children is for their mother to get a flu shot during pregnancy and for people around them to get vaccinated, as well. A flu shot given during pregnancy has been shown to not only protect the mother from flu, but also to help protect the baby from flu infection for several months after birth, before he or she is old enough to be vaccinated.
2. Children aged 6 months up to their 5th birthday. Since 2010, CDC estimates that flu-related hospitalizations among children younger than 5 years ranged from 7,000 to 26,000. Even children in this age group who are otherwise healthy are at high risk simply because of their age. Additionally, children 2 years of age up to their 5th birthday are more likely than healthy older children to be taken to a doctor, an urgent care center, or the emergency room because of flu ³⁾, ⁴⁾. To protect their health, all children 6 months and older should be vaccinated against flu each year. Vaccinating young children, their families, and other caregivers can also help protect them from getting sick.
3. American Indian and Alaskan Native children: These children are more likely to have severe flu illness that results in hospitalization or death ⁵⁾.
4. Children aged 6 months old through 18 years old with chronic health problems, including:
   • Asthma and other chronic lung diseases (such as chronic obstructive pulmonary disease [COPD] and cystic fibrosis)
   • Neurologic and neurodevelopment conditions [including disorders of the brain, spinal cord, peripheral nerve, and muscle such as cerebral palsy, epilepsy (seizure disorders), stroke, intellectual disability (mental retardation), moderate to severe developmental delay, muscular dystrophy, or spinal cord injury]
   • Chronic lung disease
   • Heart disease (such as congenital heart disease, congestive heart failure and coronary artery disease)
   • Blood disorders (such as sickle cell disease)
   • Endocrine disorders (such as diabetes mellitus)
   • Kidney disorders
   • Liver disorders
   • Metabolic disorders (such as inherited metabolic disorders and mitochondrial disorders)
   • Weakened immune system due to disease or medication (such as people with HIV or AIDS, or cancer, or those on chronic steroids)
   • Children who are taking aspirin or salicylate-containing medicines
   • Extreme obesity, which has been associated with severe flu illness in some studies of adults, may also be a risk factor for children. Childhood obesity is defined as a body mass index (BMI) at or above the 95th percentile, for age and sex.

Who should be prioritized for flu vaccination during a vaccine shortage?

When the flu vaccine supply is in limited supply, vaccination efforts should focus on delivering vaccination to the following people (no hierarchy is implied by order of listing):

• Children aged 6 months through 4 years (59 months);
• People aged 50 years and older;*
• People with chronic pulmonary (including asthma) or cardiovascular (except isolated hypertension), renal, hepatic, neurologic, hematologic, or metabolic disorders (including diabetes mellitus);
• People who are immunosuppressed due to any cause, including immunosuppression caused by medications or by human immunodeficiency virus (HIV) infection;
• Women who are or will be pregnant during the influenza season and women up to two weeks after delivery;
• People who are aged 6 months through 18 years who are receiving aspirin or salicylate-containing medications and who might be at risk for experiencing Reye syndrome after influenza virus infection;
• People who are residents of nursing homes and other long-term care facilities;
• American Indians/Alaska Natives;
• People with extreme obesity (body-mass index [BMI] is 40 or greater);
• Health care personnel;
• Household contacts and caregivers of children under 5 years and adults aged 50 years and older; and
• Household contacts and caregivers of people with medical conditions that put them at increased risk for severe illness and complications from influenza.

Footnote: *Among adults, complications, hospitalizations, and deaths due to influenza are generally most common among those 65 years old and over. However, adults 50 years old and over are a priority group for vaccination because this group may be more likely to have chronic medical conditions that put them at high risk of severe influenza illness.

How effective is the flu vaccine?

How well the flu vaccine works (or its ability to prevent flu illness) can vary from season to season. The vaccine’s effectiveness also can vary depending on who is being vaccinated. At least two factors play an important role in determining the likelihood that flu vaccine will protect a person from flu illness: 1) characteristics of the person being vaccinated (such as their age and health), and 2) the similarity or “match” between the flu viruses the flu vaccine is designed to protect against and the flu viruses spreading in the community. During years when the flu vaccine is not well matched to circulating influenza viruses, it is possible that little or no benefit from flu vaccination may be observed. During years when there is a good match between the flu vaccine and circulating viruses, it is possible to measure substantial benefits from flu vaccination in terms of preventing flu illness and complications. However, even during years when the flu vaccine match is good, the benefits of flu vaccination will vary, depending on various factors like the characteristics of the person being vaccinated, what influenza viruses are circulating that season and even, potentially, which type of flu vaccine was used.

CDC conducts studies each year to determine how well the influenza (flu) vaccine protects against flu illness. While vaccine effectiveness can vary, recent studies show that flu vaccination reduces the risk of flu illness by between 40% and 60% among the overall population during seasons when most circulating flu viruses are well-matched to the flu vaccine. In general, current flu vaccines tend to work better against influenza B and influenza A(H1N1) viruses and offer lower protection against influenza A(H3N2) viruses.

How effective is the flu vaccine in children?

Vaccination has been found in most seasons to provide a similar level of protection against flu illness in children to that seen among healthy adults.

In several studies, flu vaccine effectiveness was higher among children who received two doses of flu vaccine the first season that they were vaccinated (as recommended) compared to “partially vaccinated” children who only received a single dose of flu vaccine. However, in some seasons, partially vaccinated children still receive some protection.

In addition to preventing illness, flu vaccine can prevent severe, life-threatening complications in children, for example:

• A 2014 study showed that flu vaccine reduced children’s risk of flu-related pediatric intensive care unit (PICU) admission by 74% during flu seasons from 2010-2012.
• In 2017, a study in the journal Pediatrics ⁶⁾ was the first of its kind to show that flu vaccination also significantly reduced a child’s risk of dying from the flu. The study, which looked at data from four flu seasons between 2010 and 2014, found that flu vaccination reduced the risk of flu-associated death by half (51 percent) among children with underlying high-risk medical conditions and by nearly two-thirds (65 percent) among healthy children.

Types of flu vaccines for children

Children 6 months and older should get an annual flu vaccine. For the 2019-2020 flu season, CDC recommends annual influenza vaccination for everyone 6 months and older with any licensed, age-appropriate flu vaccine.

1. Injectable influenza vaccine (IIV) is given as an injection (with a needle) and is approved for use in people 6 months and older.
2. Live inactivated influenza vaccine (LAIV) is given as a nasal spray and is approved for use in people 2 through 49 years old. However, there is a precaution against the use of nasal spray flu vaccine (LAIV) in people with certain underlying medical conditions.

Your child’s health care provider will know which vaccines are right for your child.

Table 1. U.S. Influenza Vaccine Products for the 2019-2020 Season

Trade Name [Manufacturer]	Presentation	Age Indication	HA, µG/dose (each virus)	Egg-grown virus, Cell culture-grown virus, or Recombinant HA	Adjuvanted Yes/No	Latex Yes/No	Thimerosal Yes/No If yes, Mercury, μg/0.5mL
Quadrivalent IIVs (IIV4s)
Afluria Quadrivalent* Seqirus	0.25 mL prefilled syringe*	6 through 35 mos*	7.5/0.25 mL	Egg	No	No	No
	0.5 mL prefilled syringe*	≥3 yrs*	15/0.5 mL	Egg	No	No	No
	5.0 mL multi-dose vial*	≥6 mos*(needle/syringe)18 through 64 yrs (jet injector)	See note for dosing*	Egg	No	No	Yes (24.5)
Fluarix Quadrivalent GlaxoSmithKline	0.5 mL prefilled syringe	≥6 mos	15/0.5mL	Egg	No	No	No
FluLaval Quadrivalent ID GlaxoSmithKline	0.5 mL prefilled syringe	≥6 mos	15/0.5mL	Egg	No	No	No
	5.0 mL multi-dose vial	≥6 mos	15/0.5mL	Egg	No	No	Yes (<25)
Flucelvax Quadrivalent Seqirus (ccIIV4)	0.5 mL prefilled syringe	≥4 yrs	15/0.5mL	Cell	No	No	No
	5.0 mL multi-dose vial	≥4 yrs	15/0.5mL	Cell	No	No	Yes (25)
Fluzone Quadrivalent †Sanofi Pasteur	0.25 mL prefilled syringe†	6 through 35 mos†	7.5/0.25 mL	Egg	No	No	No
	0.5 mL prefilled syringe†	≥6 mos†	15/0.5 mL	Egg	No	No	No
	0.5 mL single-dose vial†	≥6 mos†	See note for dosing†	Egg	No	No	No
	5.0 mL multi-dose vial†	≥6 mos†	See note for dosing†	Egg	No	No	Yes (25)
Trivalent IIV (IIV3s)
Fluad Seqirus (aIIV3)	0.5 mL prefilled syringe	≥65 yrs	15/0.5mL	Egg	Yes	No	No
Fluzone High-Dose Sanofi Pasteur (HD-IIV3)	0.5 mL prefilled syringe	≥65 yrs	60/0.5mL	Egg	No	No	No
Quadrivalent RIV (RIV4)
Flublok Quadrivalent Sanofi Pasteur	0.5 mL prefilled syringe	≥18 yrs	45/0.5mL	Recombinant	No	No	No

Footnotes: * for Afluria Quadrivalent, children aged 6 through 35 months should receive 0.25mL per dose. Persons ≥36 months (≥3 years) should receive 0.5mL per dose.

† for Fluzone Quadrivalent, children aged 6 through 35 months may receive either 0.25mL or 0.5mL per dose. Persons ≥36 months (≥3 years) should receive 0.5mL per dose

Abbreviations: IIV=inactivated influenza vaccine; RIV=recombinant influenza vaccine; HA=hemagglutinin; months=months; yrs=years.

[Source ⁷⁾ ]

Who SHOULD NOT get the flu shot

People who SHOULD NOT get the flu shot:

1. Children younger than 6 months of age are too young to get a flu shot.
2. People with severe, life-threatening allergies to flu vaccine or any ingredient in the vaccine. This might include gelatin, antibiotics, or other ingredients.

People who should talk to their health care provider before getting a flu shot:

If you have one of the following conditions, talk with your health care provider. He or she can help decide whether vaccination is right for you, and select the best vaccine for your situation:

• If you have an allergy to eggs or any of the ingredients in the vaccine. Talk to your doctor about your allergy. See Special Considerations Regarding Egg Allergy for more information about egg allergies and flu vaccine.
• If you ever had Guillain-Barre syndrome a severe paralyzing illness (also called GBS). Some people with a history of Guillain-Barre syndrome should not get a flu vaccine. Talk to your doctor about your Guillain-Barre syndrome history.
• If you are not feeling well, talk to your doctor about your symptoms.

Special consideration regarding egg allergy

People with egg allergies can receive any licensed, recommended age-appropriate influenza (flu) vaccine (IIV, RIV4, or LAIV4) that is otherwise appropriate. People who have a history of severe egg allergy (those who have had any symptom other than hives after exposure to egg) should be vaccinated in a medical setting, supervised by a health care provider who is able to recognize and manage severe allergic reactions.

What is Guillain-Barre syndrome?

Guillain-Barré syndrome (GBS) is a rare disorder in which a person’s own immune system — which usually attacks only invading organisms — damages their nerve cells, causing muscle weakness and sometimes paralysis. Guillain-Barre syndrome can cause symptoms that usually last for a few weeks. Most people recover fully from Guillain-Barre syndrome, but some people have long-term nerve damage. In very rare cases, people have died of Guillain-Barre syndrome, usually from difficulty breathing. In the United States, an estimated 3,000 to 6,000 people develop Guillain-Barre syndrome each year.

Once thought to be a single disorder, Guillain-Barre syndrome is now known to occur in several forms. The main types are:

1. Acute inflammatory demyelinating polyradiculoneuropathy (AIDP), the most common form in North America and Europe. In AIDP the nerves’ protective covering (myelin sheath) is damaged. The damage prevents nerves from transmitting signals to your brain, causing weakness, numbness or paralysis. The most common sign of AIDP is muscle weakness that starts in the lower part of your body and spreads upward.
2. Miller Fisher syndrome (MFS), in which paralysis starts in the eyes. MFS is also associated with unsteady gait. MFS is less common in the U.S. but more common in Asia.
3. Acute motor axonal neuropathy (AMAN) and acute motor-sensory axonal neuropathy (AMSAN) are less common in the U.S. But AMAN and AMSAN are more frequent in China, Japan and Mexico.

What causes Guillain-Barre syndrome?

The exact cause of Guillain-Barre syndrome is unknown, but about two-thirds of people who develop Guillain-Barre syndrome experience symptoms several days or weeks after they have been sick with diarrhea or a respiratory illness. Infection with the bacterium Campylobacter jejuni is one of the most common risk factors for Guillain-Barre syndrome. People also can develop Guillain-Barre syndrome after having the flu or other infections (such as cytomegalovirus and Epstein Barr virus). On very rare occasions, they may develop Guillain-Barre syndrome in the days or weeks after getting a vaccination.

Rarely, recent surgery can also trigger Guillain-Barre syndrome. Recently, there have been Guillain-Barre syndrome cases reported following infection with the Zika virus.

Risk factors for developing Guillain-Barre syndrome

Guillain-Barre syndrome can affect all age groups. But your risk increases as you age. It’s also more common in males than females.

Guillain-Barre syndrome may be triggered by:

• Most commonly, infection with campylobacter, a type of bacteria often found in undercooked poultry
• Influenza virus
• Cytomegalovirus
• Epstein-Barr virus
• Zika virus
• Hepatitis A, B, C and E
• HIV, the virus that causes AIDS
• Mycoplasma pneumonia
• Surgery
• Trauma
• Hodgkin’s lymphoma
• Rarely, influenza vaccinations or childhood vaccinations

Who is at risk for developing Guillain-Barre syndrome?

Anyone can develop Guillain-Barre syndrome; however, it is more common among older adults. The incidence of Guillain-Barre syndrome increases with age, and people older than 50 years are at greatest risk for developing Guillain-Barre syndrome.

What are symptoms of Guillain-Barre syndrome?

Guillain-Barre syndrome often begins with tingling and weakness starting in your feet and legs and spreading to your upper body and arms. In about 10% of people with the disorder, symptoms begin in the arms or face. As Guillain-Barre syndrome progresses, muscle weakness can evolve into paralysis.

Signs and symptoms of Guillain-Barre syndrome may include:

• Prickling, pins and needles sensations in your fingers, toes, ankles or wrists
• Weakness in your legs that spreads to your upper body
• Unsteady walking or inability to walk or climb stairs
• Difficulty with facial movements, including speaking, chewing or swallowing
• Double vision or inability to move eyes
• Severe pain that may feel achy, shooting or cramplike and may be worse at night
• Difficulty with bladder control or bowel function
• Rapid heart rate
• Low or high blood pressure
• Difficulty breathing

People with Guillain-Barre syndrome usually experience their most significant weakness within two weeks after symptoms begin.

Guillain-Barre syndrome complications

Guillain-Barre syndrome affects your nerves. Because nerves control your movements and body functions, people with Guillain-Barre may experience:

• Breathing difficulties. The weakness or paralysis can spread to the muscles that control your breathing, a potentially fatal complication. Up to 22% of people with Guillain-Barre syndrome need temporary help from a machine to breathe within the first week when they’re hospitalized for treatment.
• Residual numbness or other sensations. Most people with Guillain-Barre syndrome recover completely or have only minor, residual weakness, numbness or tingling.
• Heart and blood pressure problems. Blood pressure fluctuations and irregular heart rhythms (cardiac arrhythmias) are common side effects of Guillain-Barre syndrome.
• Pain. One-third of people with Guillain-Barre syndrome experience severe nerve pain, which may be eased with medication.
• Bowel and bladder function problems. Sluggish bowel function and urine retention may result from Guillain-Barre syndrome.
• Blood clots. People who are immobile due to Guillain-Barre syndrome are at risk of developing blood clots. Until you’re able to walk independently, taking blood thinners and wearing support stockings may be recommended.
• Pressure sores. Being immobile also puts you at risk of developing bedsores (pressure sores). Frequent repositioning may help avoid this problem.
• Relapse. From 2% to 5% of people with Guillain-Barre syndrome experience a relapse.

Severe, early symptoms of Guillain-Barre syndrome significantly increase the risk of serious long-term complications. Rarely, death may occur from complications such as respiratory distress syndrome and heart attacks.

Guillain-Barre syndrome diagnosis

Guillain-Barre syndrome can be difficult to diagnose in its earliest stages. Its signs and symptoms are similar to those of other neurological disorders and may vary from person to person.

Your doctor is likely to start with a medical history and thorough physical examination.

Your doctor may then recommend:

• Spinal tap (lumbar puncture). A small amount of fluid is withdrawn from the spinal canal in your lower back. The fluid is tested for a type of change that commonly occurs in people who have Guillain-Barre syndrome.
• Electromyography. Thin-needle electrodes are inserted into the muscles your doctor wants to study. The electrodes measure nerve activity in the muscles.
• Nerve conduction studies. Electrodes are taped to the skin above your nerves. A small shock is passed through the nerve to measure the speed of nerve signals.

Guillain-Barre syndrome treatment

There’s no cure for Guillain-Barre syndrome. But two types of treatments can speed recovery and reduce the severity of the illness:

• Plasma exchange (plasmapheresis). The liquid portion of part of your blood (plasma) is removed and separated from your blood cells. The blood cells are then put back into your body, which manufactures more plasma to make up for what was removed. Plasmapheresis may work by ridding plasma of certain antibodies that contribute to the immune system’s attack on the peripheral nerves.
• Immunoglobulin therapy. Immunoglobulin containing healthy antibodies from blood donors is given through a vein (intravenously). High doses of immunoglobulin can block the damaging antibodies that may contribute to Guillain-Barre syndrome.

These treatments are equally effective. Mixing them or administering one after the other is no more effective than using either method alone.

You are also likely to be given medication to:

• Relieve pain, which can be severe
• Prevent blood clots, which can develop while you’re immobile

People with Guillain-Barre syndrome need physical help and therapy before and during recovery. Your care may include:

• Movement of your arms and legs by caregivers before recovery, to help keep your muscles flexible and strong
• Physical therapy during recovery to help you cope with fatigue and regain strength and proper movement
• Training with adaptive devices, such as a wheelchair or braces, to give you mobility and self-care skills

Guillain-Barre syndrome recovery

Although some people can take months and even years to recover, most people with Guillain-Barre syndrome experience this general timeline:

• After the first signs and symptoms, the condition tends to progressively worsen for about two weeks
• Symptoms reach a plateau within four weeks
• Recovery begins, usually lasting six to 12 months, though for some people it could take as long as three years.

Among adults recovering from Guillain-Barre syndrome:

• About 80% can walk independently six months after diagnosis
• About 60% fully recover motor strength one year after diagnosis
• About 5% to 10% have very delayed and incomplete recovery

Children, who rarely develop Guillain-Barre syndrome, generally recover more completely than adults.

When should children get a flu vaccine?

Children should be vaccinated every flu season for the best protection against flu. The best time to get a flu vaccine is before flu season starts in October. For children who will need two doses of flu vaccine, the first dose should be given as early in the season as possible. For other children, it is good practice to get them vaccinated by the end of October. It’s best to get vaccinated as soon as this year’s flu vaccine becomes available, which usually is around September. This gives the body time to build immunity before the winter flu season. However, getting vaccinated later can still be protective, as long as flu viruses are circulating. While seasonal flu outbreaks can happen as early as October, during most seasons flu activity peaks between December and February. Since it takes about two weeks after vaccination for antibodies to develop in the body that protect against flu virus infection, it is best that people get vaccinated so they are protected before influenza begins spreading in their community.

You also can protect yourself against the flu (and many other infections) by washing your hands well and often.

Side effects of flu shot in babies and toddlers

The viruses in a flu shot are killed (inactivated), so you cannot get flu from a flu shot. Some minor side effects that may occur are:

• Soreness, redness, and/or swelling where the shot was given
• Headache (low grade)
• Fever
• Muscle aches
• Nausea
• Fatigue

Common side effects from a flu shot include soreness, redness, and/or swelling where the shot was given, headache (low grade), fever, nausea, muscle aches, and fatigue. The flu shot, like other injections, can occasionally cause fainting.

Life-threatening allergic reactions to influenza shots are very rare. Signs of serious allergic reaction can include breathing problems, hoarseness or wheezing, hives, paleness, weakness, a fast heartbeat, or dizziness. If they do occur, it is usually within a few minutes to a few hours after receiving the shot. These reactions can occur among persons who are allergic to something that is in the vaccine, such as egg protein or other ingredients. While severe reactions are uncommon, you should let your doctor, nurse, clinic, or pharmacist know if you have a history of allergy or severe reaction to influenza vaccine or any part of influenza vaccine.

There is a small possibility that influenza vaccine could be associated with Guillain-Barré syndrome. Guillain–Barre syndrome occurs within 6 weeks following a previous dose of influenza vaccine and generally no more than 1 or 2 cases per million people vaccinated. This is much lower than the risk of severe complications from influenza, which can be prevented by influenza vaccine.

How common is Guillain-Barre syndrome among people who have been vaccinated against flu?

The background rate for Guillain-Barre syndrome in the Unites States is about 80 to 160 cases of Guillain-Barre syndrome each week, regardless of vaccination. The data on the association between Guillain-Barre syndrome and seasonal flu vaccination are variable and inconsistent across flu seasons. If there is an increased risk of Guillain-Barre syndrome following flu vaccination it is small, on the order of one to two additional Guillain-Barre syndrome cases per million doses of flu vaccine administered.