COVID-19 affects every person differently. Even if they weigh the same and suffer from the same health conditions, they can develop different symptoms and face different difficulties. This is one of the mysteries that scientists are still trying to unravel. Based on the many researches conducted so far, genes, gender, environment, diet and many other factors can increase the chances of serious infection and even developing COVID for a long time. In another attempt to understand the nature of the infectious virus, scientists recently conducted a detailed study that found that a person’s nails can tell whether they are at risk of contracting COVID-19 for a long time.