Both flu and COVID-19 can spread before symptoms appear. Flu virus may spread for about one day before symptoms, while the virus that causes COVID-19 may spread for about two days before symptoms, according to the Centers for Disease Control and Prevention. (Photo courtesy of CDC)

Infectious disease experts across the country have been warning about the unusual circumstances and complications the ongoing pandemic will cause during the upcoming influenza season, which normally begins in fall and can last through late spring.

The Centers for Disease Control and Prevention recommends annual influenza vaccination for everyone 6 months and older with any licensed, age-appropriate flu vaccine with no preference expressed for any one vaccine over another. This year is no exception to that recommendation, even as COVID-19 is still spreading, infecting and killing people.

Here the CDC provides answers to the biggest questions being posed to health experts as flu season approaches.

What viruses will the 2020-21 flu vaccines protect against?

There are many different flu viruses and they are constantly changing. The composition of U.S. flu vaccines is reviewed annually and updated as needed to match circulating flu viruses. Flu vaccines protect against the three or four viruses (depending on the vaccine) that research suggests will be most common.

Do we need to get a flu vaccine earlier this year?

There is no change in CDC’s recommendation on timing of vaccination this flu season. Getting vaccinated in July or August is too early, especially for older people, because of the likelihood of reduced protection against flu infection later in the flu season.

September and October are good times to get vaccinated. However, as long as flu viruses are circulating, vaccination should continue, even in January or later.

Will there be changes in how and where the flu vaccine is given this fall and winter?

How and where people get a flu vaccine may need to change due to the COVID-19 pandemic. The CDC works with healthcare providers and state and local health departments to develop contingency plans on how to vaccinate people against flu without increasing their risk of exposure to respiratory germs, like the virus that causes COVID-19, and has released Interim Guidance for Immunization Services During the COVID-19 Pandemic.

Some settings that usually provide flu vaccine, like workplaces, may not offer vaccination this upcoming season, because of the challenges with maintaining social distancing.

For more information on where you can get a flu vaccine, visit www.vaccinefinder.org.

How many flu vaccines are expected to be available for the 2020-21 flu season?

Flu vaccine is produced by private manufacturers, so supply depends on manufacturers. For the 2020-21 season, manufacturers have projected they will provide as many as 194 million to 198 million doses of flu vaccine, which is more than the 175 million dose record set during the 2019-20 flu season.

Are there delays in the availability of the flu vaccine?

Currently, vaccine manufacturers are not reporting any significant delays in distributing the flu vaccine this season. Because a record number of flu vaccine doses are being manufactured this year, the time to produce and distribute them will be longer. The CDC will continue to provide weekly updates on total flu vaccine doses distributed throughout the 2020-21 flu season.

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.

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, the 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.

Can I have flu and COVID-19 at the same time?

Yes. It is possible to 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.

With the COVID-19 pandemic still spreading, getting a flu vaccine is more important than ever to prevent and reduce the severity of flu-related illness, according to health experts. (Photo courtesy of the CDC)

The Food and Drug Administration has given CDC an Emergency Use Authorization for this new test. Initial test kits were sent to public health laboratories in early August. The CDC will continue to manufacture and distribute these kits.

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.

Is COVID-19 more dangerous than the 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.

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.

If 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. 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 the 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.

To learn more about COVID-19, visit Coronavirus (COVID-19). To learn more about flu, visit Influenza (Flu).