January 13, 2022
Author/Medically reviewed by: Dana Hawkinson, MD, and Elizabeth W. Musil, MD
Flu is a contagious respiratory illness caused by influenza viruses that infect the nose, throat and sometimes the lungs. Symptoms range from mild to severe and can lead to death. The best way to prevent flu is by getting a flu vaccine annually.
Flu activity typically begins in late October to early November and lasts until the end of spring or late May. The height of flu season is usually between December and February making this season particularly infectious with the increasing rise of COVID-19-postive cases. In fact, you may have of heard the term “flurona,” which is used to describe the condition of having both influenza and COVID-19 at the same time.
Dana Hawkinson, MD, medical director of infection prevention and control at The University of Kansas Health System, says it’s critical that everyone 6 months of age and older get an annual flu vaccine.
Additionally, Dr. Hawkinson says many of the steps we take to protect ourselves from contracting the deadly coronavirus will also help during flu season. COVID-19 has caused more than 830,000 deaths in the United States since the beginning of the pandemic.
"Wearing a mask, washing your hands frequently and keeping your distance from others – those measures will help protect us from influenza as well," says Dr. Hawkinson.
Both COVID-19 and flu can have varying signs and symptoms, ranging from no symptoms to severe symptoms. Common symptoms that COVID-19 and flu share include:
- Fever or feeling feverish/chills
- Cough
- Shortness of breath or difficulty breathing
- Fatigue (tiredness)
- Sore throat
- Runny or stuffy nose
- Muscle pain or body aches
- Headache
- Vomiting or diarrhea
Both COVID-19 and flu can spread among people who are in close contact with one another and both are spread primarily by droplets made when people with the illness cough, sneeze or talk. The droplets can land in the mouths, noses or eyes of people nearby or be inhaled into the lungs.
Wearing a mask, washing your hands frequently and keeping your distance from others – those measures will help protect us from influenza as well. ‒ Dana Hawkinson, MD
Medical director, infection prevention and control
Differences between the flu and COVID-19
Flu usually comes on suddenly, anywhere from 1 to 4 days after infection, while COVID-19 symptoms may appear 2-14 days after exposure to the virus. According to the Centers for Disease Control and Prevention (CDC), someone exposed to COVID-19 typically develops symptoms 5-6 days after being infected, but that time span can vary.
Another symptom of COVID-19 that distinguishes it from the flu is a change in or loss of taste or smell that often occurs with the COVID-19 Delta variant and less often, but still present, in the Omicron variant. Temporary loss of smell and taste has been tied to COVID-19 infection.
The CDC wants to ensure you take steps to care for yourself by getting a flu shot and understanding the difference between COVID-19 and the flu.
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 called SARS-CoV-2, and flu is caused by infection with influenza viruses. Because COVID-19 is a new virus, it seems to be spreading through the human population much faster than flu. With the flu, most of us are carrying some level of antibody protection from a previous year's exposure or from a vaccine. Additionally, the fatality rate is much higher for COVID-19 than the flu. These are both more dangerous than the common cold.
The flu spreads through droplets – sneezing, coughing, blowing your nose – and can stay on surfaces for up to a day. So, if someone with the flu touches a surface and you touch it a short time after them, you could become infected. That’s why handwashing and covering you/your child’s mouth when you/they sneeze or cough is so important.
For both COVID-19 and flu, it’s possible to spread the virus for at least 1 day before experiencing any symptoms. But, if a person has COVID-19, they may be contagious for a longer time period than if they had flu. In addition, many people with COVID-19 do not have symptoms or have mild symptoms they don’t recognize. Because they do not realize they are ill, they are more likely to spread the virus to others.
Whether it’s fever, chills, sore throat, cough, runny/stuffy nose, headache, stomachache and/or body aches, COVID-19, flu, and the common cold symptoms can look the same. A distinction: The flu is more of a respiratory virus, whereas COVID-19 is sometimes accompanied by vomiting or diarrhea. Flu symptoms can last for up to a week.
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.
September and October are good times to get vaccinated. However, as long as flu viruses are circulating, vaccination should continue.
Yes, it’s safe. Multiple vaccines, including the COVID-19 vaccine, can be administered in the same visit. If you or your child have a strong immune response to vaccines, vaccines could be administered about two weeks apart. Just remember, it takes about 2 weeks for the body to build up an antibody response. All people at least 6 months of age without certain underlying conditions can receive a flu vaccine, while those 5 years and older can receive a COVID-19 vaccine. According to the CDC, people 12 years and older should get their COVID-19 booster.
Getting a flu vaccine will not protect against COVID-19; however, flu vaccination has many other important benefits. Flu vaccines help reduce the risk of flu illness, hospitalization and death. Getting a vaccine this flu season will be more important than ever, not only to reduce your risk from flu but also to help conserve potentially scarce healthcare resources.
The flu viruses are smart, constantly changing to get around our defenses and make us sick. The CDC works year-round to collect data and determine which strains will be most prevalent year to year. So, unlike the childhood immunizations that generally stay the same, the flu vaccine works to provide the most up-to-date protection for that specific season.
There are lots of misconceptions about the flu shot. Is it 100% effective at preventing the flu? No. Scientists do their best to create a vaccine based on the research they’ve done on the previous year’s flu strains. Although effectiveness does vary year to year, the CDC estimates the flu vaccine reduces your risk of getting the flu by 40-60% when the vaccine is well matched to circulating viruses. It’s also important to note that if you get the flu shot and still get the flu, symptoms will last for a shorter period and will not be as severe. You also have a lower risk of flu-related complications (like dehydration, hospitalization, pneumonia, blood infections, etc.).
More, the flu vaccine has been shown to significantly reduce the risk of death in children. A study published in Pediatrics in 2017 showed that between 2010 and 2014, the flu vaccine reduced the risk of flu-related death by 51% among children with other high-risk medical conditions. It also reduced the risk of death in healthy children by 65%. Equally important, getting your child vaccinated protects those around them – older adults who may have weakened immune systems, people with cancer, and babies too young to be vaccinated.
If it’s your child’s first flu season receiving the shot and they are 9 years old or younger, 2 doses will be administered 4 weeks apart. This helps prime their immune system – the first shot shows their body what the flu viruses look like and the second shot is a reminder to make even more protective antibodies (memory, germ-fighting cells). When a child gets 2 doses of the flu shot their first season, only 1 dose is needed for future flu seasons.
Having everyone else in the house (or those around the baby) vaccinated and practicing good handwashing are the best ways to keep your baby safe. If you have older kids in the house, teach them about handwashing, sneezing/coughing into their arms, and trying to avoid kissing the baby if they are sick.
Luckily, you cannot get the flu from the flu shot – the influenza virus in the flu shot is inactive (dead). Feeling crummy after you get a shot actually means your immune system is doing its job, working to create antibodies to protect you in the future. When you get a vaccine, an inflammatory response is triggered in your body, a similar type of response like when you get an infection. It’s the same reason kids sometimes get a fever after their childhood immunizations – their immune system is getting to work. So sometimes you may feel feverish or achy after getting a shot, but it’s a small price to pay for how sick you could get if you caught the actual illness. The most common complaint we hear after giving a flu shot is some soreness where the shot was given.
Treating the flu
Since the flu is caused by viruses, antibiotics won’t help. Instead, focus on comfort and hydration. Remember to push fluids such as water, Pedialyte or Gatorade. You can also try things like popsicles or applesauce. In kids 2 years or older, it’s important they pee at least 3 times in 24 hours. In kids younger than 2, it’s important they pee at least 4 times in 24 hours. In addition to rest and hydration, Tamiflu may ease symptoms.
Tamiflu is an antiviral medication that may help shorten the duration of symptoms, depending on when it’s started in the course of the illness. It tends to work best when started within the first 48 hours of symptom onset. There are liquid and capsule forms. Sometimes pharmacies run out of the liquid form, but capsules can be opened and sprinkled on applesauce or pudding for kids. This medicine is not appropriate for everyone, so ask a doctor if your or your child could benefit from it. Like any medication, there are potential side effects, the most common ones being headache, fussiness, and nausea/vomiting/upset stomach. Kids sometimes report hallucinations. If this happens, medication should be stopped immediately.
Schedule a flu shot at your local pharmacy or call your provider’s office.