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 new coronavirus (called SARS-CoV-2) and flu is caused by infection with influenza viruses. Because some of the symptoms of flu and COVID-19 are similar, it may be hard to tell the difference between them based on symptoms alone, and testing may be needed to help confirm a diagnosis. Flu and COVID-19 share many characteristics, but there are some key differences between the two.
While more is learned every day, there is still a lot that is unknown about COVID-19 and the virus that causes it. This table compares COVID-19 and flu, given the best available information to date.
To learn more about COVID-19, visit Coronavirus (COVID-19).
To learn more about flu, visit Influenza (Flu).
Will there be flu along with COVID-19 in the fall and winter?
While it’s not possible to say with certainty what will happen in the fall and winter, CDC believes it’s likely that flu viruses and the virus that causes COVID-19 will both be spreading. In this context, getting a flu vaccine will be more important than ever. CDC recommends that all people 6 months and older get a yearly flu vaccine.
Can I have flu and COVID-19 at the same time?
Yes. It is possible have flu, as well as other respiratory illnesses, and COVID-19 at the same time. Health experts are still studying how common this can be.
Some of the symptoms of flu and COVID-19 are similar, making it hard to tell the difference between them based on symptoms alone. Diagnostic testing can help determine if you are sick with flu or COVID-19.
Is there a test that can detect both flu and COVID-19?
Yes. CDC has developed a test that will check for A and B type seasonal flu viruses and SARS CoV-2, the virus that causes COVID-19. This test will be used by U.S. public health laboratories. Testing for these viruses at the same time will give public health officials important information about how flu and COVID-19 are spreading and what prevention steps should be taken. The test will also help public health laboratories save time and testing materials, and to possibly return test results faster.
The Food and Drug Administration (FDA) has given CDC an Emergency Use Authorizationexternal icon for this new test. Initial test kits were sent to public health laboratories in early August 2020. CDC will continue to manufacture and distribute these kits.
More information for laboratories is available.
Will the new test that detects both flu and COVID-19 replace other tests?
No. This new test is designed for use at CDC-supported public health laboratories at state and local levels, where it will supplement and streamline surveillance for flu and COVID-19. The use of this specialized test will be focused on public health surveillance efforts and will not replace any COVID-19 tests currently used in commercial laboratories, hospitals, clinics, and other healthcare settings.
CDC’s first viral test for SARS-CoV-2 (the CDC 2019-nCoV Real-Time RT-PCR Diagnostic Panel (ER-34)) will still be available for qualified laboratories to order through the International Reagent Resource (IRR)external icon. The new multiplex assay can also be ordered through the IRR. Check the IRR website for details.
For additional questions, please visit: Clinical Questions about COVID-19: Questions and Answers: Testing, Diagnosis, and Notification
Is COVID-19 more dangerous than flu?
Flu and COVID-19 can both result in serious illness, including illness resulting in hospitalization or death. While there is still much to learn about COVID-19, at this time, it does seem as if COVID-19 is more deadly than seasonal influenza; however, it is too early to draw any conclusions from the current data. This may change as we learn more about the number of people who are infected who have mild illnesses.
Will a flu vaccine protect me against COVID-19?
Getting a flu vaccine will not protect against COVID-19, however flu vaccination has many other important benefits. Flu vaccines have been shown to reduce the risk of flu illness, hospitalization and death. Getting a flu vaccine this fall will be more important than ever, not only to reduce your risk from flu but also to help conserve potentially scarce health care resources.
Does a flu vaccination increase your risk of getting COVID-19?
There is no evidence that getting a flu vaccination increases your risk of getting sick from a coronavirus, like the one that causes COVID-19.
You may have heard about a studyexternal icon published in January 2020 that reported an association between flu vaccination and risk of four commonly circulating seasonal coronaviruses, but not the one that causes COVID-19. This report was later found to be incorrect.
The results from that initial study led researchers in Canada to look at their data to see if they could find similar results in their population. The results from Canada’s studyexternal icon showed that flu vaccination did not increase risk for these seasonal coronaviruses. The Canadian findings highlighted the protective benefits of flu vaccination.
The Canadian researchers also identified a flaw in the methods of the first study, noting that it violated the part of study design that compares vaccination rates among patients with and without flu (test negative design). This flaw led to the incorrect association between flu vaccination and seasonal coronavirus risk. When these researchers reexamined data from the first study using correct methods, they found that flu vaccination did not increase risk for infection with other respiratory viruses, including seasonal coronaviruses.
What is CDC doing to promote flu vaccination during the COVID-19 pandemic?
To address the importance of influenza vaccination, especially during the COVID-19 pandemic, CDC will maximize flu vaccination by increasing availability of vaccine, including purchasing an additional 2 million doses of pediatric flu vaccine and 9.3 million doses of adult flu vaccine, by emphasizing the importance of flu vaccination for the entire flu season, and by conducting targeted communication outreach to specific groups who are at higher risk for complications from flu. These same groups are often at higher risk for COVID-19 too, so protecting them from influenza is important to decrease their risk of co-infection. Communication strategies for providers and the public will include:
If coronavirus disease 2019 (COVID-19) is spreading in my community, should I still go out to get a flu vaccine?
Yes. Getting a flu vaccine is an essential part of protecting your health and your family’s health this season. To protect your health when getting a flu vaccine, follow CDC’s recommendations for running essential errands and doctor visits. Continue to take everyday preventive actions.
How can I safely get a flu vaccine if COVID-19 is spreading in my community?
When going to get a flu vaccine, practice everyday preventive actions and follow CDC recommendations for running essential errands.
Ask your doctor, pharmacist, or health department if they are following CDC’s vaccination pandemic guidance. Any vaccination location following CDC’s guidance should be a safe place for you to get a flu vaccine.
If I am at high risk for serious illness from COVID-19 or flu, where is the safest place for me to get a flu vaccine?
You can safely get a flu vaccine at multiple locations including your doctor’s office, health departments, and pharmacies. You can use VaccineFinder.orgexternal icon to find where flu vaccines are available near you. When going to get a flu vaccine, be sure to practice everyday preventive actions.
Ask your doctor, pharmacist, or health department if they are following CDC’s vaccination pandemic guidance. Any vaccination location following CDC’s guidance should be a safe place for you to get a flu vaccine.
Vaccination of people at high risk for flu complications is especially important to decrease their risk of severe flu illness. Many people at higher risk from flu also seem to be at higher risk from COVID-19. If you are at high risk, it is especially important for you to get a flu vaccine this year.
Are there special precautions my doctor, pharmacist, or health department should take this flu season to make sure flu vaccines can be given safely during the COVID-19 pandemic?
Yes. CDC has resources to help with vaccine planning during the COVID-19 pandemic. Ask your doctor, pharmacist, or health department if they are following CDC’s vaccination pandemic guidance. And protect yourself by practicing everyday preventive actions.
I don’t have a primary care provider, where can I get a flu vaccine?
If you don’t have a doctor that you regularly see, flu vaccines are also available at locations including health departments and pharmacies. You can use VaccineFinder.orgexternal icon to find where flu vaccines are available near you.
Source: CDC