COVID-19, which stands for coronavirus disease of 2019, is an infection caused by a type of coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The infection we know as “the flu” is caused by the influenza virus.

Both are viral, respiratory illnesses, but they are not the same thing. It is because coronavirus and influenza are different viruses, a vaccine or treatment for one won’t have any effect on the other. That is the flu vaccine will not prevent you from getting COVID-19.

Coronavirus vs. Flu Deaths 

The first thing to know is that deaths due to COVID-19 and the flu are not counted in the same way. This means comparing the numbers isn’t as straightforward as we would like. Each death due to influenza in the U.S. does not have to be reported, so there is never a direct count. Each flu season, the CDC estimates deaths from the flu based on in-hospital deaths and death certificate data. They continue to update the data on their website as they collect it. Therefore, numbers from the last two flu seasons are not considered final just yet. As more people are being tested, the case fatality ratio will decrease.

CDC estimates that influenza was associated with more than 35.5 million illnesses, more than 16.5 million medical visits, 490,600 hospitalizations, and 34,200 deaths during the 2018–2019 influenza season. Other publications suggest in 2018, 80,000 people died from the flu, a bad year as the flu vaccine didn’t work very well.

Both coronavirus and influenza: 

*Are spread by respiratory droplets and close contact.  *Can be spread by infected people without symptoms.  *Can also be spread by infected surfaces or objects, although this is less likely.  *Do not respond to antibiotics, which are meant to treat bacterial (not viral) infections.                                         

To make matters worse, we know that people can be infected with coronavirus and another respiratory virus simultaneously, which is called coinfection. So, it’s possible to have COVID-19 and the flu at the same time.

Long-term effects of COVID-19

Unfortunately, we don’t know much yet about the long-term effects of COVID-19. It can clearly affect multiple systems in the body, and experts fear there may be long-term neurological, cardiac, and respiratory harm. It is important to mention, that all viruses have the potential for post illness complications, such as loss of sense of smell, loss of hearing, and vertigo just to mention a few. Think of Herpes, chickenpox-shingles, and EBV just to name a few.

COVID-19 Onset 2-14 days after exposure Flu Onset 1-4 days after exposure

Similar symptoms

• Fever

• Fatigue (feeling tired)

• Body aches/muscle pain

• Headaches

• Nasal congestion or runny nose

• Cough

• Sore throat

• Shortness of breath (less common with Flu)

• Nausea, vomiting, diarrhea

Disease course COVID Wide range; depends upon illness severity Flu 3-5 days to 14 days

Contagious period

COVID

2-14 days BEFORE symptoms

10 days AFTER symptoms (also 10 days after testing positive if asymptomatic)

Flu

1 day BEFORE symptoms

5-7 days AFTER symptoms