“Will there be another wave of Covid-19? And if so, how big will it be, and will there be more waves after it?
The answer to those questions depend on seasonality, the susceptibility of the population to the disease, the rate at which the coronavirus mutates and how we come out of lockdown.
Colds and influenza are seasonal because those viruses generally survive outside the body for a shorter time in high heat and high humidity than in cold weather and low humidity. People also spend more time indoors in winter, coming into close contact with others with less ventilation, so respiratory infections are far more common in winter, although of course they can sicken people in summer, too.
But in 1918 and 1919, the years of the world’s deadliest pandemic, the seasons seemed to have little impact on the influenza.”