COVID-19, widely known as the coronavirus, is spreading across the globe in ways not seen in over 100 years. The 1918 influenza pandemic, known as the Spanish Flu, infected over 500 million people worldwide and killed an estimated 50 million over its course. Since reports of COVID-19 began this past winter, this new disease has often been compared to the Spanish Flu in its scope and to seasonal influenza in its symptoms, but that isn’t an entirely accurate comparison.
First, let’s look at the ways that COVID-19 and the flu are similar. Both are infectious respiratory illnesses, attacking the nose, throat, and lungs in various ways. Both are viruses, which means they cannot be treated with antibiotics. Both can result in pneumonia or serious respiratory distress in severe cases.
COVID-19 and the flu can share some symptoms, such as:
- Fever
- Cough
- Body aches
- Fatigue
- Runny nose
- Nasal congestion
- Sore throat
- Vomiting
- Diarrhea
- Loss of appetite
- Headache
- Shortness of breath
COVID-19 and the flu can be transmitted from person to person contact or through droplets from coughing, sneezing, or talking. Both can live on surfaces for hours or days, depending on the material and environment. And both the flu and COVID-19 can be transmitted by someone who isn’t sick or experiencing symptoms, making it more difficult to control and track the spread of disease.
You can protect yourself and others from both COVID-19 and the flu by practicing good hygiene through thorough hand washing, covering your mouth when you sneeze or cough, and disinfecting shared surfaces like door handles, handrails, keyboards, computer mice, phones, tables, and cooking spaces. And social distancing – maintaining at least six feet between you and people not within your household – can make a huge difference in slowing the spread of both illnesses.
Now, let’s look at the key ways that COVID-19 differs from the flu. One virus causes COVID-19: severe acute respiratory syndrome coronavirus 2, or SARS-CoV-2. The flu is caused by any of several different types and strains of influenza viruses, which often differ year from year. Unlike the flu, evidence has shown that COVID-19 may be airborne. This means that droplets containing the virus can remain in the air for a certain amount of time after being expelled by an ill person, possibly infecting people nearby.
According to the WHO, there is also a difference in the speed of transmission. The flu can spread faster than COVID-19, and its symptoms generally appear sooner. Flu symptoms typically manifest within 1–4 days of infection, while COVID-19 symptoms can take between 1–14 days to appear. This means that someone who has been exposed to COVID-19 needs to quarantine for at least two weeks.
The most alarming difference between COVID-19 and the flu is COVID-19’s severity and mortality rate. The WHO estimates that around 15% of COVID-19 cases are severe and 5% are critical; critical cases require a ventilator in order to breathe.
COVID-19 can be far more deadly than the flu. While rates vary widely by country, the mortality rate for COVID-19 appears to be between 4% and 6%. This is compared to a less than 1% seasonal mortality rate for the flu.
There is one more key difference between COVID-19 and the flu, and it’s one that will hopefully soon end: Currently, there is no vaccine for COVID-19.