Flu is often used for comparison when discussing measures against a Covid 19 pandemic. The World Health Organization (WHO) now lists important similarities and differences:
The form of infectious diseases is similar. Both are respiratory diseases caused by a virus, the course of which can vary greatly – from asymptomatic or mild to very severe, sometimes even fatal. Both pathogens are predominantly transmitted via droplets, for example when speaking or coughing, or through direct contact. That is why the same precautions apply to both: good hand hygiene, coughing in the elbows or a handkerchief, avoiding contact with infected people.
Symptoms frequency table
Propagation speed different
According to the WHO, there are differences in the speed of propagation. Influenza had a shorter incubation period between infection and the development of the first symptoms, and the infection in the infection chains was quicker. For Covid-19 this interval is about five to six days, for influenza three days. This means that influenza can spread faster than Covid-19.
In addition, influenza often infects other people even before symptoms develop. With Covid-19, transmissions are known 24 to 48 hours before the onset of symptoms, but according to the current state of knowledge, they are rare, unlike with the flu, and hardly played a role in the spread.
Children less affected than adults
Another important indicator is the infection rate. According to WHO data, the new coronavirus Sars-CoV-2 is passed on from one infected person to an average of two to two and a half other people – and thus to more than with influenza. Because of the uncertain data situation and various effects influencing the value, a comparison in this aspect is only possible to a limited extent, according to the WHO.
There are significant differences with regard to children: “Children are important drivers of the transmission of influenza viruses in the community,” said the WHO. For the Covid 19 pathogen, initial evaluations showed that children are less affected than adults and rarely develop clear symptoms. According to preliminary data, it can also be assumed that children become infected primarily in adults – but conversely adults hardly in children.
Covid-19 more often life threatening
According to previous evaluations, there are more severe to life-threatening courses with Covid-19 than with the flu. According to the WHO, the course in 15 percent of those infected is so difficult that an additional supply of oxygen is necessary. Accordingly, artificial respiration is necessary for five percent of those infected. The death rate is probably higher than with the normal seasonal flu wave – exact details can hardly be given at the moment.
Children, pregnant women, the elderly, and people with chronic diseases or a weakened immune system are considered to be particularly at risk from influenza in severe cases. At Covid-19, children and pregnant women do not belong to the risk groups according to current knowledge.
No vaccines for Covid-19 yet
The difference in the options for treatment and preventive care must also be noted. “While there are a number of clinical drug trials in China and there are more than 20 vaccines against Covid-19 in development, there are no approved vaccines or therapies for Covid-19,” reports the WHO. With influenza, however, there are both protective vaccinations and approved antiviral drugs.