Fluzone is a brand-name vaccine that’s FDA-approved for preventing influenza (the flu). Specifically, Fluzone protects against influenza types A and B.

Fluzone is available in the following two forms:

  • Fluzone Quadrivalent. This vaccine can be used in adults and children ages 6 months and older.
  • Fluzone High-Dose Quadrivalent. This vaccine can be used in adults ages 65 years and older.

Both forms of Fluzone comes as liquids. They’re given by healthcare providers as an injection into your muscle (an intramuscular injection).

Fluzone Quadrivalent is available in prefilled syringes that come in two sizes: 0.25 milliliters (mL) and 0.5 mL. It’s also available in 0.5-mL and 5-mL vials. Fluzone High-Dose Quadrivalent comes in 0.7-mL prefilled syringes.

To learn more about the different forms of Fluzone, see the “Fluzone High-Dose Quadrivalent vs. Fluzone Quadrivalent vs. Flublok” section below.

Effectiveness

For information on the effectiveness of Fluzone, see the “Fluzone uses” section below.

Fluzone is a biologic drug that’s available only as a brand-name medication. It doesn’t come in a biosimilar form.

A biologic drug is made from living cells, while other drugs are made from chemicals. Drugs made from chemicals can have generics, which are exact copies of the active drug in the brand-name medication. Biologics, on the other hand, can’t be copied exactly. Therefore, instead of a generic, biologics have biosimilars. Biosimilars are “similar” to the parent drug, and they’re considered to be just as effective and safe.

Like generics, biosimilars are often less expensive compared with brand-name medications.

Fluzone is available in two forms: Fluzone High-Dose Quadrivalent and Fluzone Quadrivalent. The manufacturer of Fluzone also makes a third influenza (flu) vaccine, called Flublok.

You may be wondering about the similarities and differences between these three vaccines. Below, we describe how they’re alike and different.

If you have additional questions about these vaccines, talk with your doctor or pharmacist.

Uses

Fluzone High-Dose Quadrivalent, Fluzone Quadrivalent, and Flublok vaccines all provide protection against the flu. They’re each made to match seasonal strains of the flu virus that are passed around each year. This includes both influenza types A and B.

These flu vaccines differ in the age groups for which they can be prescribed. Each vaccine is approved for use as follows:

  • Fluzone High-Dose Quadrivalent is approved for use in people ages 65 years and older.
  • Fluzone Quadrivalent is approved for use in people ages 6 months and older.
  • Flublok is approved for use in people ages 18 years and older.

Vaccine details

Fluzone High-Dose Quadrivalent, Fluzone Quadrivalent, and Flublok all come as a liquid. And they’re all given by healthcare providers as an injection into your muscle (an intramuscular injection). Typically, the vaccines are injected into your shoulder muscle.

In addition, all three vaccines are quadrivalent flu vaccines. This means they each contain four strains of the flu.

And all three vaccines are “inactive.” This means they don’t contain any live flu virus. So you can’t get sick with the flu by receiving the vaccines.

About Fluzone High-Dose Quadrivalent

Fluzone High-Dose Quadrivalent differs from the other vaccines in the amount of antigen it contains. The antigen is the part of the flu vaccine that causes your immune system to make antibodies against the flu virus. (Antibodies are proteins that help your body fight off infections, such as influenza.) And having those antibodies protects you from getting the flu.

The amount of antigen in Fluzone High-Dose Quadrivalent is four times higher than the amount of antigen in standard flu vaccines, such as Fluzone Quadrivalent and Flublok. This high amount is meant to provide a stronger immune system response in older people, who may have a higher risk of the flu and its complications. That’s why Fluzone High-Dose Quadrivalent is only approved for use in people ages 65 years and older.

About Fluzone Quadrivalent

Fluzone Quadrivalent is the standard version of Fluzone that’s generally used in most people. Fluzone Quadrivalent is approved for use in people ages 6 months and older. It’s one of the most commonly used flu vaccines because of its approval for such a wide range of ages.

About Flublok

Flublok is different from the other two flu vaccines because it’s egg-free. Fluzone High-Dose Quadrivalent and Fluzone Quadrivalent are both made using eggs. So people who are allergic to eggs should avoid receiving Fluzone High-Dose Quadrivalent and Fluzone Quadrivalent. Instead, people with an egg allergy should get Flublok.

Flublok is approved for use in people ages 18 years and older.

Fluzone can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while taking Fluzone. These lists don’t include all possible side effects.

For more information on the possible side effects of Fluzone, talk with your doctor or pharmacist. They can give you tips on how to deal with any side effects that may be bothersome.

Note: The Food and Drug Administration (FDA) tracks side effects of drugs it has approved. If you would like to report to the FDA a side effect you’ve had with Fluzone, you can do so through MedWatch.

Mild side effects of Fluzone High-Dose Quadrivalent and Fluzone Quadrivalent

Below we describe mild side effects* of both Fluzone High-Dose Quadrivalent and Fluzone Quadrivalent. Most of these side effects may go away within a few days or a couple of weeks. But if they become more severe or don’t go away, talk with your doctor or pharmacist.

Mild side effects of both Fluzone High-Dose Quadrivalent and Fluzone Quadrivalent in adults can include:

  • feeling tired or unwell
  • headache
  • muscle aches
  • pain, redness, or swelling at the injection site

* The list above is a partial list of mild side effects from Fluzone High-Dose Quadrivalent and Fluzone Quadrivalent. To learn about other mild side effects, talk with your doctor or pharmacist, or visit the prescribing information for Fluzone High-Dose Quadrivalent influenza vaccine and Fluzone Quadrivalent influenza vaccine.

Serious side effects of Fluzone High-Dose Quadrivalent and Fluzone Quadrivalent

Serious side effects from both Fluzone High-Dose Quadrivalent and Fluzone Quadrivalent aren’t common, but they can occur. Call your doctor right away if you have serious side effects. Call 911 or your local emergency number if your symptoms feel life threatening or if you think you’re having a medical emergency.

Serious side effects of both vaccines, and their symptoms, can include:

  • Allergic reaction, which is described in more detail in the “Side effects detail” section below.

Side effects in children

In clinical studies, similar to adults, the most common side effect in children who received Fluzone was injection site reactions. These reactions occur at the place where a vaccine is injected.

In children ages 6 months though 8 years, common injection site reactions included:

  • pain
  • redness
  • swelling
  • tenderness

There were also certain side effects in children ages 6 months through 35 months who received Fluzone that didn’t occur in adults. These side effects included:

  • abnormal crying
  • drowsiness
  • fever
  • irritability
  • loss of appetite
  • vomiting

If you’re concerned about side effects of Fluzone that may affect a child, talk with your doctor or pharmacist.

Side effect details

You may wonder how often certain side effects occur with this drug. Here’s some detail on certain side effects this drug may cause.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Fluzone. But it isn’t known how many people who took Fluzone in clinical studies had an allergic reaction to the vaccine.

Symptoms of a mild allergic reaction can include:

  • skin rash
  • itchiness
  • flushing (warmth and redness in your skin)

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include:

  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your tongue, mouth, or throat
  • trouble breathing

According to the Centers for Disease Control and Prevention (CDC), for every 1 million doses of influenza (flu) vaccines given, on average, about 1 to 2 people have a severe allergic reaction. And keep in mind that these reactions can be treated with certain medications.

Call your doctor right away if you have a severe allergic reaction to Fluzone. But call 911 or your local emergency number if your symptoms feel life threatening or if you think you’re having a medical emergency.

Muscle pain

It’s possible that you’ll experience muscle aches and pain after you get Fluzone. In clinical studies, here’s how often muscle pain was reported for Fluzone compared to two trivalent influenza vaccines:

Fluzone vaccineTrivalent influenza vaccines*
In children ages 6 months through 35 months26.7%25.0% to 26.6%
In children ages 3 years through 8 years38.6%34.1% to 38.4%
In adults ages 18 through 64 years23.7%16.8% to 25.3%
In adults ages 65 years and older18.3%14.2% to 18.3%

Trivalent influenza (flu) vaccines contain three strains of the flu virus. This is unlike Fluzone, which contains four strains.

According to the Centers for Disease Control and Prevention (CDC), people who get muscle pain after receiving Fluzone typically have this side effect soon after receiving the vaccine. And their muscle pain usually gets better after 1 to 2 days.

After getting Fluzone, tell your doctor if you have muscle pain that’s severe or lasts longer than a few days. They may recommend ways to help reduce your discomfort.

Headache

You may have a headache after getting Fluzone. In clinical studies, here’s how often headache was reported:

Fluzone vaccineTrivalent influenza vaccines*
In children ages 6 months through 35 months8.9%9.4% to 12.2%
In children ages 3 years through 8 years23.1%21.2% to 24.4%
In adults ages 18 through 64 years15.8%18% to 18.4%
In adults ages 65 years and older13.4%11.6%

Trivalent influenza (flu) vaccines contain three strains of the flu virus. This is unlike Fluzone, which contains four strains.

According to the Centers for Disease Control and Prevention (CDC), people who have a headache after receiving Fluzone typically have one soon after getting the vaccine. And their headache usually gets better after 1 to 2 days.

If you develop a headache that’s severe or lasts longer than a few days after getting Fluzone, call your doctor. They may recommend ways to help reduce your pain.

Feeling unwell

Some people feel unwell after they get Fluzone. This feeling is also known as malaise. Malaise can refer to any of the following symptoms:

  • overall weakness
  • discomfort
  • feeling like you’re sick or have an illness
  • simply not being well

In addition, people with malaise often feel very fatigued (have a low energy level).

In clinical studies, here’s how often malaise was reported:

Fluzone vaccineTrivalent influenza vaccines*
In children ages 6 months through 35 months38.1%32.4% to 35.2%
In children ages 3 years through 8 years31.9%32.8% to 33.4%
In adults ages 18 through 64 years10.5%12.1% to 14.7%
In adults ages 65 years and older10.7%6.3% to 11.6%

Trivalent influenza (flu) vaccines contain three strains of the flu virus. This is unlike Fluzone, which contains four strains.

According to the Centers for Disease Control and Prevention (CDC), people who have malaise after receiving Fluzone typically felt this way soon after getting the vaccine. And their malaise usually gets better after 1 to 2 days.

If you have malaise that’s severe or lasts longer than a few days after getting Fluzone, call your doctor. They may recommend ways to help you feel better.

You may wonder how Fluzone compares with other vaccines that are prescribed for similar uses. Here we look at how Fluzone and Fluad are alike and different.

Ingredients

Fluzone and Fluad are both inactivated influenza (flu) vaccines that protect against the flu. Specifically, these vaccines protect against influenza virus types A and B. (Inactivated vaccines don’t contain any live virus.)

Fluzone comes in two forms: Fluzone Quadrivalent and Fluzone High-Dose Quadrivalent. These forms are described further in the “Fluzone uses” section below.

Fluzone is a quadrivalent flu vaccine. This means it contains four different strains of the flu. Fluad, on the other hand, is a trivalent flu vaccine. It contains three different strains of the flu.

Vaccine antigens and adjuvants

Fluzone High-Dose Quadrivalent differs from other flu vaccines in the amount of antigen it contains. The antigen is the part of the flu vaccine that cause your immune system to make antibodies against the flu virus. (Antibodies are proteins that help your body fight off infections, such as influenza.) And having those antibodies protects you from getting the flu.

The amount of antigen in Fluzone High-Dose Quadrivalent is four times higher than the amount of antigen in standard flu vaccines, such as Fluzone Quadrivalent. This high amount is meant to provide a stronger immune response in older people, who may be at higher risk for influenza and its complications.

Fluad differs from Fluzone in that it contains an adjuvant. An adjuvant is something added to a vaccine to help your immune system respond better to the vaccine. The adjuvant in Fluad, called MF59, is made from squalene oil. (This oil is found naturally in animals, plants, and humans.) Adjuvants such as MF59 are helpful for protecting older people against the flu. This is because as people age, their immune system becomes weaker in fighting off infections.

Uses

Fluzone and Fluad vaccines are all approved to protect against influenza types A and B. These vaccines are approved for use in the following age groups:

  • Fluzone Quadrivalent is approved for use in people ages 6 months and older.
  • Fluzone High-Dose Quadrivalent is approved for use in people ages 65 years and older.
  • Fluad is approved for use in people ages 65 years and older.

Drug forms and administration

Fluzone High-Dose Quadrivalent, Fluzone Quadrivalent, and Fluad all come as liquids. They’re given by healthcare providers as injections into your muscle (an intramuscular injection).

Side effects and risks

Fluzone and Fluad can cause very similar side effects, but some different ones as well. Below are examples of these side effects.

Mild side effects

These lists contain up to 10 of the most common mild side effects that can occur with each vaccine, or with both Fluzone and Fluad when they’re used individually.

  • Can occur with Fluzone:
    • abnormal crying*
    • drowsiness*
    • fever*
    • irritability*
    • loss of appetite*
  • Can occur with Fluad:
    • nausea
    • diarrhea
  • Can occur with both Fluzone and Fluad:
    • vomiting*
    • pain, redness, or swelling at the injection site
    • feeling tired or unwell
    • headache

* In clinical studies, these side effects were only reported in children ages 6 months through 35 months for Fluzone.

Serious side effects

These lists contain examples of serious side effects that can occur with Fluzone, with Fluad, or with both vaccines when they’re used individually.

  • Can occur with Fluzone:
    • no unique serious side effects
  • Can occur with Fluad:
  • Can occur with both Fluzone and Fluad:

Effectiveness

Fluzone and Fluad vaccines are all approved to protect people ages 65 years and older against influenza types A and B.

These vaccines haven’t been directly compared in clinical studies. But separate studies have found both Fluzone and Fluad to be effective in protecting adults ages 65 years and older from influenza types A and B.

Currently, the Centers for Disease Control and Prevention (CDC) recommends that most people get a flu vaccine that’s appropriate for their age during flu season. The CDC doesn’t state a preference for one influenza vaccine product over another.

Costs

According to estimates on GoodRx.com, Fluzone and Fluad generally cost about the same. The actual price you’ll pay for either vaccine depends on your insurance plan, your location, and the pharmacy you use.

The Fluzone dosage your doctor prescribes will depend on several factors. These include:

  • your age
  • the form of Fluzone you take
  • in children, whether they’ve received a flu vaccine in the past

The following information describes dosages that are commonly used or recommended. Your doctor will determine the best dosage to fit your needs.

Drug forms and strengths

Fluzone influenza (flu) vaccine is available in two forms: Fluzone Quadrivalent and Fluzone High-Dose Quadrivalent. Both forms come as liquids that are injected by healthcare providers into your muscle (an intramuscular injection).

Fluzone Quadrivalent is available in prefilled syringes that come in two sizes: 0.25 milliliters (mL) and 0.5 mL. It’s also available in 0.5-mL and 5-mL vials.

Fluzone High-Dose Quadrivalent comes in 0.7-mL prefilled syringes.

Dosage of Fluzone High-Dose Quadrivalent

Fluzone High-Dose Quadrivalent is approved to protect against influenza (the flu) in adults ages 65 years and older. The recommended dose for this use is one 0.7-mL injection of the vaccine.

Dosage of Fluzone Quadrivalent

Fluzone Quadrivalent is approved to protect against influenza (the flu) in people ages 6 months and older. For people ages 9 years and older, the recommended dose for this use is one 0.5-mL injection of the vaccine.

For dosage information for people younger than 9 years of age, see the “Pediatric dosage” section just below.

Pediatric dosage

Fluzone Quadrivalent is approved for use in people ages 6 months and older. The dosage of this vaccine for children younger than 9 years old is different than it is for people ages 9 years or older. Below, we describe recommended dosages of Fluzone Quadrivalent for people younger than 9 years of age.

Dosage in children ages 6 months through 35 months

For children ages 6 months through 35 months, their Fluzone Quadrivalent dose will depend on whether they’ve gotten a flu vaccine in the past. For instance:

  • Children who haven’t received a flu vaccine in the past should receive two doses of Fluzone Quadrivalent. Each of these two doses may be either 0.25 mL or 0.5 mL. And the doses should be given at least 4 weeks apart. Your child’s doctor will determine the correct dosage for your child.
  • Children who’ve gotten a flu vaccine in the past can receive either one or two doses of Fluzone Quadrivalent. And each of these doses may be either 0.25 mL or 0.5 mL. If two doses of Fluzone Quadrivalent are recommended, the doses should be given at least 4 weeks apart. Your child’s doctor will determine the correct dosage for your child.

Dosage in children ages 36 months through 8 years

For children ages 36 months through 8 years, their Fluzone Quadrivalent dose will depend on whether they’ve gotten a flu vaccine in the past. For example:

  • Children who haven’t received a flu vaccine in the past should receive two 0.5-mL doses of Fluzone Quadrivalent. These two doses should be given at least 4 weeks apart. Your child’s doctor will determine the correct dosage for your child.
  • Children who’ve gotten a flu vaccine in the past can receive either one or two 0.5-mL doses of Fluzone Quadrivalent. If two doses are recommended, they should be given at least 4 weeks apart. Your child’s doctor will determine the correct dosage for your child.

Dosage questions

Below, we answer some common questions related to getting doses of Fluzone influenza (flu) vaccine.

When should I get my dose of Fluzone?

According to the Centers for Disease Control and Prevention (CDC), you should get a flu vaccine, such as Fluzone, in the early fall before flu season begins. Preferably, you should receive your flu vaccine by the end of October. This is because it takes about 2 weeks once you’ve gotten the flu vaccine for your body to form antibodies against the flu. (Antibodies are proteins that help your body fight infections, such as influenza.)

However, the CDC notes that getting vaccinated too early in the season may cause decreased flu protection for you later in the flu season. For example, you might not be as protected from the flu if you get your flu shot in July or August instead of getting it a bit later in the season.

If you’d like to know more about when to get your flu vaccine, talk with your doctor or pharmacist.

How often should I get a dose of Fluzone?

The Centers for Disease Control and Prevention (CDC) recommends that most people ages 6 months and older receive a flu vaccine, such as Fluzone, every year. This is for two main reasons.

First, many different strains of influenza circulate each year. And these strains are continuously changing. Each year, scientists try to determine which strains of the flu will be the most common in the upcoming flu season. Then these strains are put into flu vaccines, such as Fluzone. So flu vaccines change from year to year.

Second, the protection provided by the vaccine wanes (slowly decreases) over time. This effect happens in everyone, but it’s more likely to occur in older adults (although it’s not known exactly why).

For these reasons, it’s recommended that most people get a flu vaccine each year.

If I get Fluzone, but then I get the flu, do I need another dose of Fluzone?

No. If you get a Fluzone vaccine, but you still get the flu, you don’t need another dose of the vaccine. And you also shouldn’t get a dose of a different flu vaccine.

For adults, the Centers for Disease Control and Prevention (CDC) recommends only one dose of flu vaccine each flu season.

Note: Children of certain ages who are getting vaccinated for the flu for the first time may receive more than one dose of Fluzone. For more information about this, see the “Pediatric dosage” section above.

Before taking Fluzone, talk with your doctor about your health history. Fluzone may not be right for you if you have certain medical conditions or other factors affecting your health. These include:

  • Guillain-Barré syndrome. The influenza (flu) vaccine from 1976 was related to a higher risk of Guillain-Barré syndrome (GBS). This rare condition affects your nerves. If you’ve had GBS after getting a flu vaccine in the past, be sure to tell your doctor or pharmacist. They’ll help determine if it’s safe for you to get another flu vaccine such as Fluzone.
  • Weakened immune system. Fluzone may not work as well in people who are immunocompromised. (This is when your immune system is weakened and isn’t able to fight off infections as well as usual.) If you have any problems with your immune system, be sure to tell your doctor or pharmacist before you get Fluzone.
  • Egg allergy. Both Fluzone High-Dose Quadrivalent and Fluzone Quadrivalent are made by using eggs. If you have an egg allergy, you shouldn’t receive Fluzone. Be sure to tell your doctor or pharmacist before you get any flu vaccines if you do have an egg allergy. They can make sure you get a vaccine that’s made without using egg products.
  • Allergic reaction. If you’ve had an allergic reaction to Fluzone or any of its ingredients, you shouldn’t take Fluzone. Ask your doctor what other medications are better options for you.
  • Pregnancy. According to the Centers for Disease Control and Prevention (CDC), pregnant women should receive their yearly flu vaccine. This is because pregnant women have a higher risk of being hospitalized with the flu. For more information, see the “Fluzone and pregnancy” section below.
  • Breastfeeding. According to the Centers for Disease Control and Prevention (CDC), vaccines given to a nursing female don’t affect the safety of breastfeeding. For more information, please see the “Fluzone and breastfeeding” section below.

Note: For more information about the potential negative effects of Fluzone, see the “Fluzone side effects” section above.

Here are answers to some frequently asked questions about Fluzone.

What age do I need to be to take Fluzone?

This depends on the form of Fluzone you’re taking:

  • Fluzone Quadrivalent is approved for use in people ages 6 months and older.
  • Fluzone High-Dose Quadrivalent is approved for use in adults ages 65 years old and older.

For more information on which form of Fluzone you should take based on your age, see the “Fluzone dosage” section above. And if you have additional questions about which flu vaccine is best for you, talk with your doctor or pharmacist.

Is Fluzone a preservative-free vaccine?

Whether or not Fluzone contains a preservative depends on the form of Fluzone you’re referring to. Keep in mind that Fluzone comes in two forms: Fluzone Quadrivalent and Fluzone High-Dose Quadrivalent.

Most Fluzone Quadrivalent products are preservative-free. This is true for:

  • 0.25-mL and 0.5-mL prefilled syringes of Fluzone Quadrivalent
  • 0.5-mL vials of Fluzone Quadrivalent

However, 5-mL vials of Fluzone Quadrivalent contain thimerosal, which is a preservative that’s made from mercury. These vials of Fluzone contain multiple doses of the vaccine. And thimerosal helps prevent bacteria from growing inside the multidose vials. Thimerosal has been found to be safe when given in vaccines. This is because it’s only present in very small amounts in each vaccine dose.

Like prefilled syringes of Fluzone Quadrivalent, prefilled syringes of Fluzone High-Dose Quadrivalent are preservative-free.

So the only form of Fluzone that’s made with preservatives is Fluzone Quadrivalent that comes in 5-mL vials.

If you’d like to know whether a Fluzone vaccine you’ll be receiving contains preservatives, ask your doctor or pharmacist.

If I’ve had a flu vaccine in the past, do I need to have another one?

Yes. Even if you’ve received an influenza (flu) vaccine in the past, you’ll likely need to get another one each year.

In fact, the Centers for Disease Control and Prevention (CDC) recommends that most people older than 6 months of age receive a flu vaccine, such as Fluzone, every year. This is for two main reasons.

First, many different strains of influenza circulate each year. And these strains are continuously changing. Each year, scientists try to determine which strains of the flu will be the most common in the upcoming flu season. Then these strains are put into flu vaccines, such as Fluzone. So flu vaccines change from year to year.

Second, the protection provided by the vaccine wanes (slowly decreases) over time. This effect happens in everyone, but it’s more likely to occur in older adults (although it’s not known exactly why).

If you have questions about getting an annual flu shot, talk with your doctor or pharmacist.

Will getting Fluzone make me get the flu?

No. Flu vaccines that are given with a needle, such Fluzone, contain inactivated influenza virus. Inactivated viruses aren’t live, so they won’t make you sick.

When you get an inactivated flu vaccine, your immune system gets exposed to the inactivated flu virus. This prompts your immune system to make antibodies against the strains of flu contained in the vaccine. (Antibodies are proteins that help your body fight off infections, such as influenza.) Once you have antibodies to the flu, if you’re exposed to it, your body will be more prepared to fight it off.

On the other hand, the nasal flu vaccine, called FluMist, is made using a weakened form of a live flu virus. (The nasal vaccine is given as a spray into your nose.) The live virus contained in FluMist can only reproduce and spread at cool temperatures, such as those found in your nose. It can’t spread infection to your lungs, for example. So when the virus is contained to your nose, it shouldn’t cause a flu infection in your body.

But it’s possible that FluMist may cause side effects that are similar to symptoms caused by the flu. These side effects, which may occur for up to a few days after you get FluMist, include:

  • runny nose
  • headache
  • cough

Does Fluzone protect against COVID-19?

No, Fluzone doesn’t protect against COVID-19, which is a disease that’s caused by the new coronavirus. Instead, Fluzone only offers protection against influenza virus, which causes the flu.

If you have questions about which infections Fluzone can and can’t protect against, talk with your doctor or pharmacist.

If I’ve had COVID-19, can I still receive Fluzone?

Yes, if you’ve had COVID-19, you can still get an influenza (flu) vaccine, including Fluzone. (COVID-19 is a disease that’s caused by the new coronavirus.)

There isn’t any evidence that getting a flu vaccine increases your risk of COVID-19. And during a pandemic, it’s very important to do all that you can to prevent illness, such as the flu. This includes getting your annual flu vaccine.

However, if you currently have COVID-19, you shouldn’t go out and get a flu vaccine. Per the Centers for Disease Control and Prevention (CDC), you should stay home and self-isolate. Once your doctor has told you that you’re no longer able to transmit the virus that causes COVID-19 to others, you can ask your doctor if Fluzone is right for you.

If you have questions about COVID-19 and flu vaccines, talk with your doctor or pharmacist.

What is Fluzone Quadrivalent Southern Hemisphere?

Fluzone Quadrivalent Southern Hemisphere is a form of Fluzone that’s meant to be used in people located in the Southern Hemisphere. (The Southern Hemisphere is the portion of Earth that’s south of the equator.)

Many different strains of influenza (flu) virus circulate each flu season. And these strains are continuously changing. Different strains of influenza are responsible for causing the flu across the globe.

Each year, scientists try to determine which strains of influenza will be the most common in the upcoming flu season. Then these strains are put into flu vaccines such as Fluzone. Different parts of the world can be affected by different strains of influenza during flu season. So different flu vaccines are made for use in different parts of the world.

If you have questions about which flu vaccine you should receive based on your location, talk with your doctor or pharmacist.

Other vaccines are available that can prevent influenza (the flu). Some may be a better fit for you than others. If you’re interested in finding an alternative to Fluzone, talk with your doctor. They can tell you about other medications that may work well for you.

It’s important to note that each of the vaccines listed below have differing ages for approved use. If you have questions about which flu vaccine is best for you, talk with your doctor or pharmacist.

Examples of flu vaccines, other than Fluzone, that may be used to prevent the flu include:

  • Afluria
  • Fluad
  • Fluarix
  • Flublok
  • Flucelvax
  • FluLaval
  • FluMist

You may wonder how Fluzone compares with other medications that are prescribed for similar uses. Here we look at how Fluzone and Afluria are alike and different.

Ingredients

Fluzone and Afluria are both inactivated vaccines that protect against influenza (the flu). (Inactivated vaccines don’t contain any live virus.) Specifically, these vaccines protect against influenza virus types A and B.

Fluzone comes in two forms: Fluzone High-Dose Quadrivalent and Fluzone Quadrivalent.

Fluzone and Afluria are both quadrivalent flu vaccines. This means they each contain four strains of the flu.

Vaccine antigen

Fluzone High-Dose Quadrivalent differs from other flu vaccines in the amount of antigen it contains. The antigen is the part of the flu vaccine that causes your immune system to make antibodies against the flu virus. (Antibodies are proteins that help your body fight off infections, such as influenza.) And having those antibodies protects you from getting the flu.

The amount of antigen in Fluzone High-Dose Quadrivalent is four times higher than the amount in standard flu vaccines, such as Fluzone Quadrivalent and Afluria. This high amount is meant to provide a stronger immune response in older people, who may be at higher risk for influenza and its complications.

Uses

Both Fluzone Quadrivalent and Afluria are approved for use in people ages 6 months and older.

In addition, Fluzone High-Dose Quadrivalent is approved for use in people ages 65 years and older.

Drug forms and administration

Fluzone High-Dose Quadrivalent, Fluzone Quadrivalent, and Afluria all come as liquids. They’re given by healthcare providers as injections into your muscle (intramuscular injections).

Side effects and risks

Fluzone and Afluria can cause very similar side effects, but some different ones as well. Below are examples of these side effects.

Mild side effects

These lists contain up to 10 of the most common mild side effects that can occur with each vaccine, or with both Fluzone and Afluria (when used individually).

  • Can occur with Fluzone:
    • abnormal crying*
    • drowsiness*
    • fever*
    • vomiting*
  • Can occur with Afluria:
    • diarrhea*
  • Can occur with both Fluzone and Afluria:
    • pain, redness, or swelling at the injection site
    • feeling tired or unwell
    • headache
    • irritability*
    • loss of appetite*

* These side effects apply to Fluzone Quadrivalent and Afluria. They don’t apply to Fluzone High-Dose Quadrivalent. In clinical studies of Fluzone Quadrivalent, these side effects were only reported in children ages 6 months through 35 months. And in clinical studies of Afluria, these side effects were only reported in people younger than 60 months of age.

Serious side effects

This list contains an example of a serious side effect that can occur with Fluzone and Afluria, when each vaccine is given individually.

Effectiveness

Fluzone and Afluria vaccines have different approved uses. But they’re all used to protect against influenza types A and B in people ages 6 months and older.

These drugs haven’t been directly compared in clinical studies. But studies have found that both Fluzone and Afluria are effective for protecting people ages 6 months and older from the flu.

Currently, the Centers for Disease Control and Prevention (CDC) recommends that most people get a flu vaccine that’s appropriate for their age during flu season. The CDC doesn’t state a preference for one influenza vaccine product over another.

Costs

According to estimates on GoodRx.com, Fluzone and Afluria generally cost about the same. The actual price you’ll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

As with all medications, the cost of Fluzone can vary. To find current prices for Fluzone in your area, check out GoodRx.com.

The cost you find on GoodRx.com is what you may pay without insurance. The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.

Before approving coverage for Fluzone, your insurance company may require you to get prior authorization. This means that your doctor and insurance company will need to communicate about your prescription before the insurance company will cover the drug. The insurance company will review the prior authorization request and decide if the drug will be covered.

With Fluzone, your insurance company may have a preference for whether you get your vaccine at a pharmacy or healthcare facility.

If you’re not sure if you’ll need to get prior authorization for Fluzone, contact your insurance company.

Financial and insurance assistance

If you need financial support to pay for Fluzone, or if you need help understanding your insurance coverage, help is available.

Sanofi Pasteur, Inc., the manufacturer of Fluzone, has an online tool that may help you estimate the cost of Fluzone High-Dose Quadrivalent. For more information about this, see the manufacturer’s website.

For additional cost assistance information about Fluzone, visit Medicine Assistance Tool’s site or talk with your doctor or pharmacist.

Biosimilar or generic version

Fluzone is a biologic drug that’s available only as a brand-name medication. It doesn’t come in a biosimilar form, which is often less expensive than a brand-name medication.

A biologic drug is made from living cells, while other drugs are made from chemicals. Drugs made from chemicals can have generics, which are exact copies of the active drug in the brand-name medication.

Biologics, on the other hand, can’t be copied exactly. Therefore, instead of a generic, biologics have biosimilars. Biosimilars are “similar” to the parent drug and are considered to be just as effective and safe.

According to the Centers for Disease Control and Prevention (CDC), Fluzone influenza (flu) vaccine is safe to take during pregnancy. The CDC recommends that pregnant women receive a yearly influenza (flu) vaccine, such as Fluzone. This is because people have an increased risk of being hospitalized with the flu during pregnancy.

In clinical trials, there weren’t any studies done in pregnant people. Animal studies were done, and they didn’t show any harmful effects when the vaccine was given during pregnancy. But it’s important to remember that animal studies don’t always predict what will happen in people.

Also keep in mind that Fluzone comes in two forms: Fluzone Quadrivalent and Fluzone High-Dose Quadrivalent. These two forms are approved for use in people of differing ages. If you’re pregnant, you should receive the form of Fluzone that’s appropriate given your age.

If you have questions about receiving a flu vaccine during pregnancy, talk with your doctor.

Live vaccines vs. inactivated vaccines in pregnancy

If you’re pregnant, it’s important that you get an inactivated flu vaccine, such as Fluzone. You shouldn’t get any live vaccines while you’re pregnant.

Inactivated flu vaccines contain a dead version of the flu virus. These vaccines don’t contain a live version of the flu virus. Live flu vaccines, on the other hand, do contain live forms of the flu virus. An example of a live flu vaccine is FluMist, which is given as a spray into your nose rather than as an injection.

The CDC recommends avoiding live vaccines during pregnancy as they may be harmful to a developing fetus. This is because, in theory, a live vaccine may transfer a virus to the fetus, causing an infection.

According to the Centers for Disease Control and Prevention (CDC), Fluzone influenza (flu) vaccine is safe to take during pregnancy. So you don’t need to avoid pregnancy simply because you’re receiving Fluzone.

For more information about taking Fluzone during pregnancy, see the “Fluzone and pregnancy” section above.

It isn’t known whether Fluzone influenza (flu) vaccine passes into human breast milk.

According to the Centers for Disease Control and Prevention (CDC), vaccines given to a breastfeeding female don’t affect the safety of breastfeeding children. In fact, the CDC states that flu vaccination can increase the amount of influenza antibodies in breast milk. (Antibodies are proteins that help your body fight off infections, such as influenza.) And this may offer added flu protection to a child who’s breastfed.

But keep in mind that children who are breastfed should still receive their own flu vaccine once they’re at least 6 months of age.

If you have questions about breastfeeding and getting Fluzone, talk with your doctor or pharmacist.

The Food and Drug Administration (FDA) approves prescription drugs such as Fluzone to treat certain conditions. Fluzone may also be used off-label for other conditions. Off-label use is when a drug that’s approved to treat one condition is used to treat a different condition.

Fluzone for preventing influenza

Fluzone is used to prevent influenza (the flu). Specifically, this vaccine protects against influenza types A and B.

Fluzone is available in the following two forms, which are approved for use in people of differing ages:

  • Fluzone Quadrivalent. This vaccine can be used in adults and children ages 6 months and older.
  • Fluzone High-Dose Quadrivalent. This vaccine can be used in adults ages 65 years and older.

Both forms of Fluzone are quadrivalent flu vaccines. This means they each contain four different strains of the flu.

What influenza is

Influenza is a respiratory illness that’s caused by influenza viruses. These viruses can be spread from person to person through respiratory droplets. Respiratory droplets are released when a person coughs, sneezes, or talks. And after the droplets are released, they can survive on surfaces for a few hours.

If respiratory droplets that contain flu virus enter your body, they can cause you to have the flu. Common symptoms of the flu can include:

Winter is the primary season for flu infections in the United States. Typically, flu season peaks in February. But you can become infected with the flu during any month of the year. Also, many different strains of flu virus are circulating each flu season. And these strains are continuously changing.

What Fluzone does

Fluzone is a vaccine that protects people from the flu. Vaccines help prepare your body to fight off an infection by exposing your immune system to a virus.

Each year, scientists try to determine which strains of the flu will be the most common in the upcoming flu season. Then these strains are put into vaccines, such as Fluzone.

Fluzone contains inactivated influenza virus. (Inactivated viruses aren’t live, so they won’t make you sick.) When you get an inactivated flu vaccine, your immune system gets exposed to the inactivated flu virus. This prompts your immune system to make antibodies against the strains of flu virus contained in the vaccine.

Antibodies are proteins that help your body fight infections, such as influenza. Once you have antibodies to the flu, if you’re later exposed to the flu, your body will be more prepared to fight it off.

Vaccine antigen

Fluzone High-Dose Quadrivalent differs from other vaccines in the amount of antigen it contains. The antigen is the part of the flu vaccine that causes your immune system to make antibodies against the flu virus. And having those antibodies protects you from getting the flu.

The amount of antigen in Fluzone High-Dose Quadrivalent is four times higher than the amount in standard flu vaccines, such as Fluzone Quadrivalent. This high amount is meant to provide a stronger immune response in older people, who may be at higher risk for influenza and its complications.

Effectiveness for preventing influenza

Both Fluzone Quadrivalent and Fluzone High-Dose Quadrivalent have been shown to be effective in preventing influenza infection.

Effectiveness of Fluzone Quadrivalent

In one study, Fluzone Quadrivalent was compared with two trivalent flu vaccines that were already on the market. (Trivalent flu vaccines contain three strains of flu virus. This is unlike Fluzone, which contains four strains.)

The researchers in this study looked to see if adults who got Fluzone Quadrivalent developed flu antibodies similarly to people who got one of the trivalent vaccines. Each adult in the study received either Fluzone Quadrivalent or a trivalent flu vaccine. Then everyone had their levels of flu virus antibodies checked 21 days later.

At the end of the study, researchers found that people who got Fluzone Quadrivalent had antibody levels within 89% to 115% of the levels that people who got one of the trivalent vaccines had.

According to the World Health Organization (WHO), flu virus antibody levels should be at least 67% when comparing a new flu vaccine to one that’s already available. So, given the results of the study, Fluzone Quadrivalent is expected to provide the same level of protection as the other flu vaccine it was compared with.

Effectiveness of Fluzone High-Dose

In one study, Fluzone High-Dose Trivalent was compared with Fluzone Trivalent. (Trivalent flu vaccines contain three strains of flu virus. This is unlike quadrivalent flu vaccines, which contain four strains. However, the effectiveness of trivalent vaccines can be used to show the effectiveness of quadrivalent vaccines since they’re made in the same way.)

Note: Trivalent versions of Fluzone are no longer available.

The researchers looked to see if either vaccine was better at preventing the flu in adults ages 65 years and older. People in this study were followed for about 7 months after getting either vaccine.

At the end of the study, the researchers found that:

  • 1.43% of people who received Fluzone High-Dose Trivalent got the flu
  • 1.89% of people who received the Fluzone Trivalent vaccine got the flu

Fluzone and children

Clinical studies have shown that Fluzone Quadrivalent is effective in preventing the flu in children ages 6 months and older.

One clinical study looked at children ages 6 months through 8 years. Children in this study got either Fluzone Quadrivalent or one of two trivalent flu vaccines that were previously on the market. (Trivalent flu vaccines contain three strains of flu virus. This is unlike Fluzone, which contains four strains.)

Then the researchers waited 28 days before checking the children’s levels of flu virus antibodies.

At the end of the study, researchers found that children who got Fluzone Quadrivalent had antibody levels within 99% to 134% of the levels that children who got one of the trivalent vaccines had.

According to the World Health Organization (WHO), flu antibody levels should be at least 67% when comparing a new flu vaccine to ones that are already available. So, given the results of the study, Fluzone Quadrivalent is expected to provide the same level of protection as the other flu vaccines it was compared with.

Fluzone is given by healthcare providers as an injection into your muscle (an intramuscular injection). It’s usually injected into your deltoid muscle, which is located in your shoulder. But infants may receive Fluzone in their thigh muscle.

You’ll receive Fluzone injections at your pharmacy, local health department, or doctor’s office.

When it’s given

The Centers for Disease Control and Prevention (CDC) recommends that most people ages 6 months and older receive a yearly influenza (flu) vaccine, such as Fluzone.

The CDC recommends that you get vaccinated in the early fall before flu season begins. Preferably, you should receive your flu vaccine by the end of October. This is because it takes about 2 weeks after getting a flu vaccine for your body to form antibodies against the flu. (Antibodies are proteins that help your body fight infections, such as influenza.)

However, the CDC notes that getting vaccinated too early in the season may cause decreased flu protection for you later in the flu season. For example, you might not be as protected from the flu if you get your flu shot in July or August.

This is because the protection provided by the vaccine wanes (slowly decreases) over time. This effect is more likely to occur in older adults, although it’s not known exactly why this is the case.

If you have questions about when you should receive your flu vaccine, talk with your doctor or pharmacist.

There aren’t any known interactions between Fluzone influenza (flu) vaccine and alcohol.

However, both Fluzone and alcohol can cause headache. It’s possible that if you have headache as a side effect of Fluzone, drinking alcohol could worsen it.

If you have questions about drinking alcohol around the time of getting Fluzone, talk with your doctor.

Fluzone influenza (flu) vaccine isn’t known to interact with other medications. And there aren’t any known interactions with supplements or foods.

However, to be safe, talk with your doctor or pharmacist before receiving Fluzone. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.

Different interactions can cause different effects. For instance, some interactions can interfere with how well a drug works. Other interactions can increase the number of side effects or make them more severe.

If you have questions about possible drug interactions that may affect you, ask your doctor or pharmacist.

Fluzone is an influenza (flu) vaccine that helps to protect you from the flu. Vaccines help prepare your body to fight off an infection by exposing your immune system to a particular virus.

The flu can be caused by many different strains of influenza virus, which circulate around the globe each flu season. Each year, scientists try to determine which strains of the flu will be the most common in the upcoming flu season. Then these strains are put into vaccines, such as Fluzone.

Fluzone contains inactivated influenza virus. (Inactivated viruses aren’t live, so they won’t make you sick.) When you get an inactivated flu vaccine, your immune system gets exposed to the inactivated flu virus. This prompts your immune system to make antibodies against the strains of flu contained in the vaccine.

Antibodies are proteins that help your body fight infections, such as influenza. Once you have antibodies to the flu, if you’re exposed to it, your body will be more prepared to fight it off.

How long does it take to work?

According to the Centers for Disease Control and Prevention (CDC), it takes about 2 weeks after you get a flu vaccine for antibodies to develop and protect you from the flu.

The following information is provided for clinicians and other healthcare professionals.

Indications

Fluzone is FDA-approved to prevent influenza infection caused by both influenza types A and B.

Fluzone is available in the following two forms:

  • Fluzone Quadrivalent. This vaccine is approved for use in adults and children ages 6 months and older.
  • Fluzone High-Dose Quadrivalent. This vaccine is approved for use in adults ages 65 years and older.

Administration

Fluzone Quadrivalent and Fluzone High-Dose Quadrivalent should both be given by intramuscular injection only.

Administration of Fluzone High-Dose Quadrivalent

Adults ages 65 years and older may receive one 0.7-mL dose of Fluzone High-Dose Quadrivalent. Preferably, it should be injected into the deltoid muscle.

Administration of Fluzone Quadrivalent

Preferably, Fluzone Quadrivalent should be injected into the deltoid muscle in people ages 3 years and older. For infants ages 6 through 11 months, the preferred site of injection is the anterior thigh. Children ages 12 through 36 months may receive Fluzone in their deltoid or anterolateral aspect of their thigh muscle.

Children ages 6 months through 35 months who have not previously received an influenza vaccination should receive two doses, either 0.25 mL or 0.5 mL, of Fluzone Quadrivalent. Administration of these doses should be separated by at least 4 weeks. Children of this age who have previously been vaccinated against influenza may receive either one or two doses of Fluzone Quadrivalent.

Children ages 36 months through 8 years who have not previously received an influenza vaccination should receive two 0.5-mL doses of Fluzone Quadrivalent. Administration of these doses should be separated by at least 4 weeks. Children of this age who have previously been vaccinated against influenza may receive either one or two doses of Fluzone Quadrivalent.

All people ages 9 years and older should receive one 0.5-mL dose of Fluzone Quadrivalent.

Mechanism of action

Fluzone is an inactivated quadrivalent vaccine that stimulates an immune response against influenza types A and B, which are contained in the vaccine.

Pharmacokinetics and metabolism

According to the Centers for Disease Control and Prevention (CDC), approximately 2 weeks are needed following influenza immunization for antibodies to develop and provide protection against infection.

Annual vaccination is recommended due to declining immunity and annual variations in circulating influenza strains.

Contraindications

Do not administer Fluzone Quadrivalent or Fluzone High-Dose Quadrivalent to people with a history of severe allergic reaction to any component of Fluzone. This includes egg proteins or any previous dose of any influenza vaccine.

Storage

Fluzone Quadrivalent products should be refrigerated at a temperature of 35°F to 46°F (2°C to 8°C). Do not freeze Fluzone.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.