INSpiREzine Germs Gone Viral! | Page 35

Measles, which is one of the most infectious diseases that we know of, has an R0 of 12-18. This means that one person with the measles can infect 12-18 other people - if no one in a given population has been vaccinated and no one has had the disease.

The seasonal flu (Influenza) has an R0 value of 1.3-1.5.

COVID-19 has an R0 value of 2-2.5.

So, what’s the big deal? The R0 numbers are really similar for COVID-19 and the flu? Let's compare.

After one round of infection, one person with the flu might infect one person whereas a person with Covid-19 would infect two people.

But, let’s take a look at the numbers after 10 rounds of infection:

After 10 rounds, someone with the flu would infect one or two people, and each of them would infect another one or two people, and each of them would infect another one or two people, and so on and so on - amounting to 56 people infected with the virus.

In comparison, with COVID-19, after 10 rounds of infection, 2047 people would be infected.

56 vs 2047 - that is why COVID-19 is much worse than the flu. This pattern is called exponential growth: as time goes on, things get bigger a whole lot faster. After a couple days, things might not be whole lot different, but after a couple weeks and months the difference is astronomical!

So despite a common symptom pattern, different spread patterns make COVID-19 mighty more contagious than the flu.