What is the difference between Influenza (Flu) and COVID-19?

Influenza (flu) and COVID-19 are both contagious respiratory illnesses, but they are caused by different viruses. COVID-19 is caused by infection with a coronavirus (SARS-CoV-2) first identified in 2019. Flu is caused by infection with a flu virus (influenza viruses).

From what we know, COVID-19 spreads more easily than flu. Efforts to maximize the proportion of people in the United States who are up to date with their COVID-19 vaccines remain critical to reducing the risk of severe COVID-19 illness and death. More information is available about COVID-19 vaccines and how well they work.

Compared with flu, COVID-19 can cause more severe illness in some people. Compared to people with flu, people infected with COVID-19 may take longer to show symptoms and may be contagious for longer periods of time.

You cannot tell the difference between flu and COVID-19 by the symptoms alone because they have some of the same signs and symptoms.  Specific testing is needed to tell what the illness is and to confirm a diagnosis. Having a medical professional administer a specific test that detects both flu and COVID-19 allows you to get diagnosed and treated for the specific virus you have more quickly. Getting treated early for COVID-19 and flu can reduce your risk of getting very sick. Testing can also reveal if someone has both flu and COVID-19 at the same time, although this is uncommon. People with flu and COVID-19 at the same time can have more severe disease than people with either flu or COVID-19 alone. Additionally, some people with COVID-19 may also be affected by post-COVID conditions (also known as long COVID).

We are learning more everyday about COVID-19 and the virus that causes it. This page compares COVID-19 and flu, given the best available information to date.

Similarities:

Both COVID-19 and flu can have varying degrees of symptoms, ranging from no symptoms (asymptomatic) to severe symptoms. Common symptoms that COVID-19 and flu share include:

• Fever or feeling feverish/having chills
• Cough
• Shortness of breath or difficulty breathing
• Fatigue (tiredness)
• Sore throat
• Runny or stuffy nose
• Muscle pain or body aches
• Headache
• Vomiting
• Diarrhea (more frequent in children with flu, but can occur in any age with COVID-19)
• Change in or loss of taste or smell, although this is more frequent with COVID-19.

Differences:

If a person has COVID-19, they could be contagious for a longer time than if they have flu.
Flu

• People with flu virus infection are potentially contagious for about one day before they show symptoms. However, it is believed that flu is spread mainly by people who are symptomatic with flu virus infection.
• Older children and adults with flu appear to be most contagious during the first 3-4 days of their illness, but some people might remain contagious for slightly longer periods.
• Infants and people with weakened immune systems can be contagious for even longer.

COVID-19

• On average, people can begin spreading the virus that causes COVID-19 2-3 days before their symptoms begin, but infectiousness peaks one day before their symptoms begin.
• People can also spread the virus that causes COVID-19 without experiencing any symptoms.
• On average, people are considered contagious for about eight days after their symptoms began.

To learn more, please visit https://www.cdc.gov/flu/symptoms/flu-vs-covid19.htm.

What’s New for 2022-2023

A few things are different for the 2022-2023 influenza (flu) season, including:

• The composition of flu vaccines has been updated.
• For the 2022-2023 flu season, there are three flu vaccines that are preferentially recommended for people 65 years and older. These are Fluzone High-Dose Quadrivalent vaccine, Flublok Quadrivalent recombinant flu vaccine and Fluad Quadrivalent adjuvanted flu vaccine.
• The recommended timing of vaccination is similar to last season. For most people who need only one dose for the season, September and October are generally good times to get vaccinated. Vaccination in July and August is not recommended for most adults but can be considered for some groups. While ideally it’s recommended to get vaccinated by the end of October, it’s important to know that vaccination after October can still provide protection during the peak of flu season.
• The age indication for the cell culture-based inactivated flu vaccine, Flucelvax Quadrivalent (ccIIV4), changed from 2 years and older to 6 months and older.
• Pre-filled Afluria Quadrivalent flu shots for children are not expected to be available this season. However, children can receive this vaccine from a multidose vial at the recommended dose.

To learn more, please visit https://www.cdc.gov/flu/season/faq-flu-season-2022-2023.htm.

Viral tests look for a current infection with SARS-CoV-2, the virus that causes COVID-19, by testing specimens from your nose or mouth. There are two main types of viral tests: nucleic acid amplification tests (NAATs) and antigen tests. In certain circumstances, one test type may be recommended over the other. All tests should be performed following FDA’s requirements.

• NAATs, such as PCR-based tests, are most often performed in a laboratory. They are typically the most reliable tests for people with or without symptoms. These tests detect viral genetic material, which may stay in your body for up to 90 days after you test positive. Therefore, you should not use a NAAT if you have tested positive in the last 90 days.
• Antigen tests* are rapid tests which produce results in 15-30 minutes. They are less reliable than NAATs, especially for people who do not have symptoms. A single, negative antigen test result does not rule out infection.  To best detect infection, a negative antigen test should be repeated at least 48 hours apart (known as serial testing). Sometimes a follow-up NAAT may be recommended to confirm an antigen test result.

*Self-tests, or at-home tests, are usually antigen tests that can be taken anywhere without having to go to a specific testing site. Follow FDA and manufacturer’s instructions, including for the number of times you may need to test. Multiple negative test results increase the confidence that you are not infected with the virus that causes COVID-19.

• You can order free self-test kits at COVIDtests.gov or purchase tests online, in pharmacies, and retail stores.
• You can also visit FDA’s website to see a list of authorized tests.
• As noted in the labeling for authorized over-the-counter antigen tests: Negative results should be treated as presumptive (meaning that they are preliminary results). Negative results do not rule out SARS-CoV-2 infection and should not be used as the sole basis for treatment or patient management decisions, including infection control decisions. Please see FDA guidance on the use of at-home COVID-19 antigen tests.

To learn more, please visit https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/testing.html#types-of-tests

Everyone 6 Months and Older Should Get a COVID-19 Vaccine

COVID-19 vaccination has many benefits and is an important tool to help protect you from severe illness, hospitalization, and death.

Even if you or your child have had COVID-19, you should still get yourself or your child vaccinated.

• Getting a COVID-19 vaccine after having COVID-19 provides added protection against the virus that causes COVID-19.
• People who already had COVID-19 and do not get vaccinated after their recovery are more likely to get COVID-19 again than those who get vaccinated after their recovery.
• If you were given monoclonal antibodies or convalescent plasma while sick with COVID-19 you do not need to wait to get vaccinated.

Before the Vaccination

If you do not regularly take over-the-counter medications, you should not take them before you get a COVID-19 vaccination.

It is not known how over-the-counter (OTC) medicines, such as ibuprofen, aspirin, or acetaminophen, might affect how well the vaccine works. You may be able to take these types of medications to reduce fever or pain after you get your vaccine to relieve any pain or discomfort resulting from possible side effects.

Get a COVID-19 vaccine with your routine medical procedures and screenings

You can combine most procedures, screenings, and vaccinations at the same appointment when you get your COVID-19 vaccination. Talk to your healthcare provider if you have questions.

Children, teens, and adults may get a COVID-19 vaccine and other vaccines, including a flu vaccine, at the same time.

Preparing children and teens for vaccination

If you are getting your child or teen vaccinated learn how you can support them and talk to them about what to expect. The experience of getting a COVID-19 vaccine will be very similar to that of getting routine vaccines.

Requesting accommodations at COVID-19 vaccination sites

• When making an appointment or arriving for vaccination, you can let staff and/or volunteers know you or your child might need some accommodations.
• People with disabilities can use the COVID-19 Vaccine Disability Information and Access Line (DIAL) to get help with COVID-19 vaccinations.

If you have allergies related to vaccines

Talk to your doctor if you:

• have had a severe allergic reaction to a previous dose to learn if you should get a different type of COVID-19 vaccine,
• are allergic to polyethylene glycol (PEG) and you should not get Pfizer-BioNTech or Moderna COVID-19 vaccine,
• are allergic to polysorbate and you should not get Novavax or J&J/Janssen COVID-19 vaccine
• if you are allergic to other types of vaccines or injectable medications for other diseases.

• If you had an immediate allergic reaction (a reaction that started within 4 hours of getting vaccinated) to a COVID-19 vaccine, but the reaction was not considered severe by a medical professional, you can receive another dose of the same vaccine under certain conditions. Your doctor may refer you to an allergy and immunology specialist for more care or advice.
• If you have had an immediate allergic reaction—even if it was not severe—to a vaccine or injectable therapy for another disease, you should discuss this with your doctor to determine which COVID-19 vaccine is best for you.

If you have allergies not related to vaccines

You should get vaccinated if you have allergies that are not related to vaccines or injectable medications such as food, pet, venom, environmental, or latex allergies. People with a history of allergies to medications taken by mouth or a family history of severe allergic reactions can also get vaccinated.

At the Vaccination Site

• You should receive a paper or electronic version of a fact sheet that tells you more about the COVID-19 vaccine you or your child received. Each approved and authorized COVID-19 vaccine has its own fact sheet that contains information to help you understand the risks and benefits of that vaccine.
• There is no charge for your COVID-19 vaccine. Your COVID-19 vaccine is free. COVID-19 vaccines are paid for with taxpayer dollars and are given free of charge to all people living in the United States, regardless of health insurance or immigration status. If anyone asks you to pay for a COVID-19 vaccine, it’s a scam.

After Getting a COVID-19 Vaccine

• Stay on site to be monitored for at least 15 minutes.
• Make sure your vaccination provider updates your vaccination card (or gives you one if this is your first dose).
• Stay up to date with the recommended COVID-19 vaccines and boosters.
• You may experience side effects after getting a COVID-19 vaccine.
• Adverse effects (serious safety problems) and severe allergic reactions are rare.
• To report any side effects, you can sign up for v-safe. V-safe is a smartphone-based tool that provides quick and confidential health check-ins via text messages and web surveys so you can quickly and easily share with CDC how you or your dependent feel after getting a COVID-19 vaccine.

Watch Video: Use v-safe to tell CDC how you’re feeling after COVID-19 vaccination [00:00:34]

Your CDC COVID-19 Vaccination Card

Keep your CDC COVID-19 vaccination card for proof of vaccination. Consider taking a picture of your card after each of your COVID-19 vaccination appointments as a backup copy.

• Bring your card to your appointment whenever you get a primary series dose or booster so that your provider can fill in information about your shot.
• If your vaccine card is full, your vaccine provider can give you another card.
• If you did not receive a CDC COVID-19 vaccination card at your first appointment, contact the vaccination provider site where you got your first shot to find out how you can get a vaccination card. You can also contact your state health department to get a copy of your vaccination record.
• Some vaccination providers and health departments may offer you access to a QR code or digital copy of your COVID-19 vaccination card in addition to giving you a physical CDC COVID-19 vaccination card. Contact your vaccination provider or local health department to learn if a digital copy of your card is available to you.
• If you were vaccinated abroad there are ways you can update your U.S. vaccination record.
• To report suspicious activity involving fake CDC COVID-19 vaccination cards, please visit Fraud Alert: COVID-19 Scams or call 1-800-HHS-TIPS.

To learn more, please visit https://www.cdc.gov/coronavirus/2019-ncov/vaccines/expect.html.

What You Need To Know

• In addition to following the recommended COVID-19 vaccination schedule, tixagevimab/cilgavimab (Evusheld), a combination of two monoclonal antibodies, should be administered to people who are moderately or severely immunocompromised every 6 months for pre-exposure prophylaxis to supplement vaccine protection. Per the product EUA, Evusheld can be given at least 2 weeks after COVID-19 vaccine. People may initiate Evusheld at any time after this interval, including between doses in the primary series and between any primary and booster doses.
• This medication can provide protection for those not expected to mount an adequate immune response following vaccination, including those who are immunocompromised due to a medical condition or immunosuppressive medication, or for those individuals for whom COVID-19 vaccination is not recommended due to a history of severe adverse reaction to COVID-19 vaccination.
• Evusheld is administered by intramuscular injection by a healthcare provider at an office or healthcare facility.
• Current locations of EVUSHELD distribution can be found here.

The current treatment guidelines [5.4 MB, 456 pages] on the use of Evusheld as pre-exposure prophylaxis:

• Tixagevimab 300 mg plus cilgavimab 300 mg (Evusheld) administered as two 3-mL intramuscular (IM) injections for adults and adolescents (aged ≥12 years and weighing ≥40 kg) who do not have SARS-CoV-2 infection, who have not been recently exposed to an individual with SARS-CoV-2 infection AND who:
  • Are moderately to severely immunocompromised or
  • Are not able to be fully vaccinated with any available COVID-19 vaccines due to history of severe adverse reactions
• Tixagevimab plus cilgavimab should be repeated every 6 months.
• Individuals who received tixagevimab 150 mg plus cilgavimab 150 mg should be given a second dose as soon as possible.
  • If the initial dose was administered ≤3 months prior, the second dose should be tixagevimab 150 mg plus cilgavimab 150 mg.
  • If the initial dose was administered >3 months prior, the second dose should be tixagevimab 300 mg plus cilgavimab 300 mg.
• Individuals should be clinically monitored after injections and observed for at least 1 hour.
• Evusheld is contraindicated in individuals with previous severe hypersensitivity reactions, including anaphylaxis, to Evusheld.
• There is not currently sufficient evidence to recommend either for or against the use of SARS-CoV-2 serologic testing to assess for immunity or guide clinical decisions about using Evusheld for pre-exposure prophylaxis. For more information, see NIH’s COVID-19 Treatment Guidelines.

Evusheld and timing with COVID-19 vaccination

• Evusheld may be given at least 2 weeks after any COVID-19 vaccine.
• After this interval, Evusheld may be initiated at any time between primary series and booster doses.
• COVID-19 vaccines may be administered at any time after Evusheld administration.
• Use of monoclonal antibodies is not a substitute for COVID-19 vaccination.

To learn more, please visit https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-care/pre-exposure-prophylaxis.html.

• Updated guidance reflects new recommendations for isolation and precautions for people with COVID-19.
• Removed Assessment for Duration of Isolation and Key Findings From Transmission Literature sections so page provides most current information.

Key Points

• People who are infected but asymptomatic or people with mild COVID-19 should isolate through at least day 5 (day 0 is the day symptoms appeared or the date the specimen was collected for the positive test for people who are asymptomatic). They should wear a mask through day 10. A test-based strategy may be used to remove a mask sooner.
• People with moderate or severe COVID-19 should isolate through at least day 10. Those with severe COVID-19 may remain infectious beyond 10 days and may need to extend isolation for up to 20 days.
• People who are moderately or severely immunocompromised should isolate through at least day 20. Use of serial testing and consultation with an infectious disease specialist is recommended in these patients prior to ending isolation.

Recommendation for Ending Isolation

For people who are mildly ill with SARS-COV-2 infection and not moderately or severely immunocompromised:

• Isolation can be discontinued at least 5 days after symptom onset (day 0 is the day symptoms appeared, and day 1 is the next full day thereafter) if fever has resolved for at least 24 hours (without taking fever-reducing medications) and other symptoms are improving.
• Loss of taste and smell may persist for weeks or months after recovery and need not delay the end of isolation​.
• A high-quality mask should be worn around others at home and in public through day 10. A test-based strategy may be used to remove a mask sooner.
• If symptoms recur or worsen, the isolation period should restart at day 0.
• People who cannot wear a mask, including children < 2 years of age and people of any age with certain disabilities, should isolate for 10 days.
• In certain high-risk congregate settings that have high risk of secondary transmission, CDC recommends a 10-day isolation period for residents.

For people who test positive, are asymptomatic (never develop symptoms) and not moderately or severely immunocompromised:

• Isolation can be discontinued at least 5 days after the first positive viral test (day 0 is the date the specimen was collected for the positive test, and day 1 is the next full day thereafter).
• A high-quality mask should be worn around others at home and in public through day 10. A test-based strategy may be used to remove a mask sooner.
• If a person develops symptoms within 10 days of testing positive, their 5-day isolation period should start over (day 0 changes to the first day of symptoms).
• People who cannot wear a mask, including children < 2 years of age and people of any age with certain disabilities, should isolate for 10 days.
• In certain high-risk congregate settings that have high risk of secondary transmission, CDC recommends a 10-day isolation period for residents.

For people who are moderately ill and not moderately or severely immunocompromised:

• Isolation and precautions can be discontinued 10 days after symptom onset (day 0 is the day symptoms appeared, and day 1 is the next full day thereafter).

For people who are severely ill and not moderately or severely immunocompromised:

• Isolation should continue for at least 10 days after symptom onset (day 0 is the day symptoms appeared, and day 1 is the next full day thereafter).
• Some people with severe illness (e.g., requiring hospitalization, intensive care, or ventilation support) may remain infectious beyond 10 days. This may warrant extending the duration of isolation and precautions for up to 20 days after symptom onset (with day 0 being the day symptoms appeared) and after resolution of fever for at least 24 hours (without the taking fever-reducing medications) and improvement of other symptoms.
• Serial testing prior to ending isolation can be considered in consultation with infectious disease experts.

For people who are moderately or severely immunocompromised (regardless of COVID-19 symptoms or severity):

• Moderately or severely immunocompromised patients may remain infectious beyond 20 days. For these people, CDC recommends an isolation period of at least 20 days, and ending isolation in conjunction with serial testing and consultation with an infectious disease specialist to determine the appropriate duration of isolation and precautions.
• The criteria for serial testing to end isolation are:
  • Results are negative from at least two consecutive respiratory specimens collected ≥ 24 hours apart (total of two negative specimens) tested using an antigen test or nucleic acid amplification test.
  • Also, if a moderately or severely immunocompromised patient with COVID-19 was symptomatic, there should be resolution of fever for at least 24 hours (without the taking fever-reducing medication) and improvement of other symptoms. Loss of taste and smell may persist for weeks or months after recovery and need not delay the end of isolation​.
  • Re-testing for SARS-CoV-2 infection is suggested if symptoms worsen or return after ending isolation and precautions.
• If a patient has persistently positive nucleic acid amplification tests beyond 30 days, additional testing could include molecular studies (e.g., genomic sequencing) or viral culture, in consultation with an infectious disease specialist.
• For the purposes of this guidance, moderate to severely immunocompromising conditions include, but might not be limited to, those defined in the interim clinical considerations for people with moderate to severe immunocompromise due to a medical condition or receipt of immunosuppressive medications or treatments.
  • Other factors, such as end-stage renal disease, likely pose a lower degree of immunocompromise, and there might not be a need to follow the recommendations for those with moderate to severe immunocompromise.
  • Ultimately, the degree of immunocompromise for the patient is determined by the treating provider, and preventive actions should be tailored to each patient and situation.

To learn more, please visit https://www.cdc.gov/coronavirus/2019-ncov/hcp/duration-isolation.html.

Effective September 1^st, 2022, CDC Director Rochelle P. Walensky, M.D., M.P.H., endorsed the CDC Advisory Committee on Immunization Practices’ (ACIP) recommendations for use of updated COVID-19 boosters from Pfizer-BioNTech for people ages 12 years and older and from Moderna for people ages 18 years and older.

Updated COVID-19 boosters add Omicron BA.4 and BA.5 spike protein components to the current vaccine composition, helping to restore protection that has waned since previous vaccination by targeting variants that are more transmissible and immune-evading.

In the coming weeks, CDC also expects to recommend updated COVID-19 boosters for other pediatric groups, per the discussion and evaluation of the data by ACIP on Sept. 1, 2022. When data are available and FDA authorizes these other types of COVID-19 boosters, CDC will quickly move to help make them available in the United States.

The Food and Drug Administration’s (FDA) authorization of updated COVID-19 boosters, and CDC’s recommendation for use, are critical next steps forward in our country’s vaccination program—a program that has helped provide increased protection against COVID-19 disease and death.

The following is attributable to Dr. Walensky:

“The updated COVID-19 boosters are formulated to better protect against the most recently circulating COVID-19 variant. They can help restore protection that has waned since previous vaccination and were designed to provide broader protection against newer variants. This recommendation followed a comprehensive scientific evaluation and robust scientific discussion. If you are eligible, there is no bad time to get your COVID-19 booster and I strongly encourage you to receive it.”

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

CDC works 24/7 protecting America’s health, safety and security. Whether disease start at home or abroad, are curable or preventable, chronic or acute, or from human activity or deliberate attack, CDC responds to America’s most pressing health threats. CDC is headquartered in Atlanta and has experts located throughout the United States and the world.

To learn more, please visit https://www.cdc.gov/media/releases/2022/s0901-covid-19-booster.html

GENERAL INFORMATION

Manufacturer: Novavax, Inc.

Number of Shots: 2 doses in the primary series, given 3–8 weeks apart.

People who are moderately or severely immunocompromised should also receive 2 doses, given 3 weeks apart (a 3rd primary dose is not currently authorized).

Booster Shot:  Novavax COVID-19 vaccine is not authorized for use as a booster dose.

Type of Vaccine: Protein subunit

How Given: Shot in the muscle of the upper arm

Does NOT Contain: Eggs, preservatives, latex, metals
See full list of ingredients

Name: NVX-CoV2373

SAFETY DATA SUMMARY

• COVID-19 vaccines have undergone—and continue to undergo—the most intensive safety monitoring in U.S. history. Side effects that happen within 7 days of getting vaccinated are common but are mostly mild and only last a few days. Some people have reactions that affect their ability to do daily activities.
• Side effects throughout the body (such as fever, chills, tiredness, and headache) are more common after the second dose of the vaccine.
• Severe allergic reactions to vaccines are rare but can happen. Cases of myocarditis and pericarditis have been reported in people who received Novavax COVID-19 vaccine.

Learn more about vaccine safety monitoring after a vaccine is authorized or approved for use.

HOW WELL THE VACCINE WORKS

• Vaccines reduce the risk of COVID-19, including the risk of severe illness and death among people who are fully vaccinated.
• COVID-19 vaccines are effective. Clinical trials demonstrate that Novavax COVID-19 reduces the risk of COVID-19, including the risk of severe illness and death. However, studies from other COVID-19 vaccines have shown that protection declines over time especially with the Omicron variant.
• All FDA-approved or authorized COVID-19 vaccines provide substantial protection against COVID-19 hospitalization and death.
• CDC will continue to provide updates as we learn more.

Learn about Novavax’s clinical trial information for people 18 years and older.

NOVAVAX COVID-19 VACCINE INGREDIENTS

COVID-19 vaccine ingredients are considered safe for most people. Nearly all of the ingredients in COVID-19 vaccines are ingredients found in many foods—fats, sugar, and salts. The Novavax COVID-19 vaccine also includes harmless pieces (proteins) of the virus that causes COVID-19; they are pieces of what is often called the spike protein.  After vaccination, the body creates an immune response to these protein pieces. This response helps protect you from getting sick with COVID-19 in the future. After the body produces an immune response, it discards all the vaccine ingredients, just as it would discard any substance that cells no longer need. This process is a part of normal body functioning.

All COVID-19 vaccines are manufactured with as few ingredients as possible and with very small amounts of each ingredient. Each ingredient in the vaccine serves a specific purpose as seen in the table below.

Type of Ingredient	Ingredient	Purpose
Protein	SARS-CoV-2 recombinant spike protein	Causes an immune response that helps protect the body from getting sick with COVID-19 in the future.
Lipids (fats)	Cholesterol Phosphatidylcholine	Work together to help the recombinant spike protein enter cells
Adjuvant	Fraction-A and Fraction-C of Quillaja saponaria Molina extract.	Facilitates activation of the cells of the innate immune system.
Salts, sugar, and acid	Disodium hydrogen phosphate heptahydrate Disodium hydrogen phosphate dihydrate Polysorbate-80 Potassium chloride (common food salt) Potassium dihydrogen phosphate (common food salt) Sodium chloride (basic table salt) Sodium dihydrogen phosphate monohydrate Sodium hydroxide or hydrochloric acid Water	Work together to help keep the vaccine molecules stable while the vaccine is manufactured, shipped, and stored until it is ready to be given to a vaccine recipient.

The vaccine may also contain very small amounts of ingredients from the manufacturing stage, which can be found in the EUA Fact Sheet.

INGREDIENTS THAT ARE NOT USED IN COVID-19 VACCINES

The above table lists ALL ingredients in the Novavax COVID-19 vaccine. There are NO ingredients in this vaccine beyond what is listed in the table. The Novavax COVID-19 vaccine has:

• No preservatives such as thimerosal or mercury or any other preservatives.
• No antibiotics such as sulfonamide or any other antibiotics.
• No medicines or therapeutics such as ivermectin or any other medications.
• No tissues such as aborted fetal cells, gelatin, or any materials from any animal.
• No food proteins such as eggs or egg products, gluten, peanuts, tree nuts, nut products, or any nut byproducts (COVID-19 vaccines are not manufactured in facilities that produce food products).
• No metals such as iron, nickel, cobalt, titanium, rare earth alloys, or any manufactured products like microelectronics, electrodes, carbon nanotubes or other nanostructures, or nanowire semiconductors.
• No latex. The vial stoppers used to hold the vaccine also do not contain latex.

To learn more, please visit https://www.cdc.gov/coronavirus/2019-ncov/vaccines/novavax.html.

Learning about how COVID-19 spreads and the factors that can increase or decrease that risk can help you make informed choices.

The questions below are written in past tense to help you assess the likelihood that you were infected when you were around a person with COVID-19. If multiple factors below indicate higher transmission risk, you should follow the steps for what to do if you are exposed.

You can also ask yourself the same questions, but about future interactions with others, to help you decide what prevention actions to take. If multiple factors below indicate higher transmission risk, you should consider adding more prevention actions.

Factors that lower or increase risk of transmission

Length of time: How long were you with the infected person?

Longer exposure time increases the risk of transmission (for example, contact longer than 15 minutes is more likely to result in transmission than two minutes of contact).

Cough or heavy breathing: Was the infected person coughing, singing, shouting, or breathing heavily?

Activities like coughing, singing, shouting, or breathing heavily due to exertion increase the risk of transmission.

Symptoms: Did the infected person have symptoms at the time?

Being around people who are symptomatic increases the risk of transmission.

Masks: Were you or the infected person or both wearing a respirator (for example, N95) or high-quality mask?

If one person was wearing a mask, the risk of transmission is decreased, and if both people were wearing masks, the risk is substantially decreased. Risk is also lower if the mask or respirator is a type that offers greater protection.

Ventilation and filtration: How well-ventilated was the space?

More outdoor air can decrease the risk of transmission. Being outside would be lower exposure risk than being indoors, even with good ventilation and filtration; both of those options would be lower risk than being indoors with poor ventilation or filtration. See the Interactive Home Ventilation Tool.

Distance: How close was the infected person to you?

Being closer to someone who is infected with COVID-19 increases the risk of transmission. Crowded settings can raise your likelihood of being close to someone with COVID-19.

To learn more, please visit https://www.cdc.gov/coronavirus/2019-ncov/your-health/risks-exposure.htm

What You Need to Know

• COVID-19 vaccines are safe and effective and severe reactions after vaccination are rare.
• CDC recommends COVID-19 vaccines for everyone ages 6 months and older, and boosters for everyone 5 years and older, if eligible.
• Millions of people in the United States have received COVID-19 vaccines under the most intense safety monitoring program in U.S. history.
• CDC, the U.S. Food and Drug Administration (FDA), and other federal agencies continue to monitor the safety of all vaccines, including COVID-19 vaccines, by reviewing data reported to the Vaccine Adverse Event Reporting System (VAERS) and the Vaccine Safety Datalink (VSD).

The benefits of COVID-19 vaccination continue to outweigh any potential risks.

CDC is providing timely updates on the following adverse events of interest:

• Anaphylaxis after COVID-19 vaccination is rare and has occurred at a rate of approximately 5 cases per one million vaccine doses administered. Anaphylaxis, a severe type of allergic reaction, can occur after any kind of vaccination. If it happens, healthcare providers can effectively and immediately treat the reaction. Learn more about COVID-19 vaccines and allergic reactions, including anaphylaxis.

CDC scientists have conducted detailed reviews of cases of anaphylaxis and made the information available to healthcare providers and the public:

• Allergic Reactions Including Anaphylaxis After Receipt of the First Dose of Pfizer-BioNTech COVID-19 Vaccine
• Reports of Anaphylaxis After Receipt of mRNA COVID-19 Vaccines in the US—December 14, 2020-January 18, 2021
• Allergic Reactions Including Anaphylaxis After Receipt of the First Dose of Moderna COVID-19 Vaccine— United States, December 21, 2020-January 10, 2021
• Allergic Reactions Including Anaphylaxis After Receipt of the First Dose of Pfizer-BioNTech COVID-19 Vaccine — United States, December 14-23, 2020
• Thrombosis with thrombocytopenia syndrome (TTS) after J&J/Janssen COVID-19 vaccination is rare and has occurred in approximately 4 cases per one million doses administered. TTS is a rare but serious adverse event that causes blood clots in large blood vessels and low platelets (blood cells that help form clots).

A review of reports indicates a causal relationship between the J&J/Janssen COVID-19 vaccine and TTS. CDC scientists have conducted detailed reviews of TTS cases and made the information available to healthcare providers and the public:

• US Case Reports of Cerebral Venous Sinus Thrombosis With Thrombocytopenia After Ad26.COV2.S Vaccination, March 2 to April 21, 2021
• Case Series of Thrombosis with Thrombocytopenia Syndrome following COVID-19 vaccination—United States, December 2020–August 2021
• Updates on Thrombosis with Thrombocytopenia Syndrome (TTS) [1.3 MB, 39 Pages]
• Guillain-Barré Syndrome (GBS) in people who have received the J&J/Janssen COVID-19 vaccine is rare. GBS is a rare disorder where the body’s immune system damages nerve cells, causing muscle weakness and sometimes paralysis. GBS has largely been reported in men ages 50 years and older.

Based on a recent analysis of data from the Vaccine Safety Datalink, the rate of GBS within the first 21 days following J&J/Janssen COVID-19 vaccination was found to be 21 times higher than after Pfizer-BioNTech or Moderna (mRNA COVID-19 vaccines). After the first 42 days, the rate of GBS was 11 times higher following J&J/Janssen COVID-19 vaccination. The analysis found no increased risk of GBS after Pfizer-BioNTech or Moderna (mRNA COVID-19 vaccines). CDC and FDA will continue to monitor for and evaluate reports of GBS occurring after COVID-19 vaccination and will share more information as it becomes available.

• Myocarditis and pericarditis after COVID-19 vaccination are rare. Myocarditis is inflammation of the heart muscle, and pericarditis is inflammation of the outer lining of the heart. Most patients with myocarditis or pericarditis after COVID-19 vaccination responded well to medicine and rest and felt better quickly. Most cases have been reported after receiving Pfizer-BioNTech or Moderna (mRNA COVID-19 vaccines), particularly in male adolescents and young adults.

A review of vaccine safety data in VAERS from December 2020–August 2021 found a small but increased risk of myocarditis after mRNA COVID-19 vaccines. Over 350 million mRNA vaccines were given during the study period and CDC scientists found that rates of myocarditis were highest following the second dose of an mRNA vaccine among males in the following age groups:

• 12–15 years (70.7 cases per one million doses of Pfizer-BioNTech)
• 16–17 years (105.9 cases per one million doses of Pfizer-BioNTech)
• 18–24 years (52.4 cases and 56.3 cases per million doses of Pfizer-BioNTech and Moderna, respectively)

Multiple studies and reviews of data from vaccine safety monitoring systems continue to show that vaccines are safe. As a result, the agency will refocus enhanced surveillance and safety monitoring efforts toward children and adolescents.

As of July 28, 2022, there have been 1,010 preliminary reports in VAERS among people younger than age 18 years under review for potential cases of myocarditis and pericarditis. Of these, 258 remain under review. Through confirmation of symptoms and diagnostics by provider interview or review of medical records, 665 reports have been verified to meet CDC’s working case definition for myocarditis. See below for counts of verified reports of myocarditis by age group.

5-11 years: 22 verified reports of myocarditis after 20,404,074 doses administered

12-15 years: 346 verified reports of myocarditis after 24,198,309 doses administered

16-17 years: 297 verified reports of myocarditis after 13,326,016 doses administered

As the COVID-19 vaccines are authorized for younger children, CDC and FDA will continue to monitor for and evaluate reports of myocarditis and pericarditis after COVID-19 vaccination and will share more information as it becomes available. Learn more about myocarditis and pericarditis, including clinical considerations, after mRNA COVID-19 vaccination.

• Reports of death after COVID-19 vaccination are rare. FDA requires healthcare providers to report any death after COVID-19 vaccination to VAERS, even if it’s unclear whether the vaccine was the cause. Reports of adverse events to VAERS following vaccination, including deaths, do not necessarily mean that a vaccine caused a health problem. More than 603 million doses of COVID-19 vaccines were administered in the United States from December 14, 2020, through July 27, 2022. During this time, VAERS received 15,700 preliminary reports of death (0.0026%) among people who received a COVID-19 vaccine. CDC and FDA clinicians review reports of death to VAERS including death certificates, autopsy, and medical records.

Continued monitoring has identified nine deaths causally associated with J&J/Janssen COVID-19 vaccination. CDC and FDA continue to review reports of death following COVID-19 vaccination and update information as it becomes available.

To learn more, please visit https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/adverse-events.html