New research data suggests that Covid-19 pandemic has seasonal characteristics. This makes their occurrence pattern oriented.
Researchers show that Covid-19 cases and mortality rates are significantly correlated with temperature and latitude across 221 countries.
The researchers downloaded relevant epidemiological data (disease incidence, mortality, recovery cases, active cases, testing rate, hospitalisation) from 221 countries, along with their latitude, longitude, and average temperature.
The research team then used statistical methods to test if epidemiological variables were correlated with temperature, latitude, and longitude. The expectation was that warmer countries closer to the equator would be the least affected.
Epidemiological analysis showed a statistically significant correlation between temperature and incidence, mortality, recovery cases, and active cases. The same tendency was found with latitude, but not with longitude.
One conclusion is that the disease may be seasonal, like the flu. This is very relevant to what we should expect from now on after the vaccine controls these first waves of Covid-19.
While temperature and latitude were unmistakably correlated with Covid-19 cases, the researchers also pointed out climate is only one factor driving seasonal Covid-19 incidence worldwide.
They also assigned each country a risk index reflecting public health preparedness and incidence of co-morbidities in the population.
The idea was that if the disease was surging in countries with inadequate resources or higher-than-average rates of diabetes, obesity, or old age, the risk index would appear more important in the analysis than temperature.
The researchers also noted that the body’s own immune system could be partially responsible for the pattern of seasonality. They believe that it is too soon to say how seasonality and our immune systems interact in the case of Covid-19.