According to a latest research from the University of London, exposure to sunlight may help stop the spread of chickenpox.Researchers have found that chickenpox is less common in regions with high UV levels, suggesting sunlight may inactivate viruses on the skin, making it more difficult to pass on. 　　Through examining 25 studies on varicella-zoster virus in various countries, researchers found UV levels are linked to chickenpox virus prevalence. Researchers believe that this partly explains why chickenpox is less common in tropical countries, while it is more common in colder seasons in colder countries, where people have less exposure to sunlight. 　　However, other researchers said that even though UV can contribute to the difference in the spread of chickenpox between tropical and temperate regions, there are other factors that need to be considered, such as heat, humidity and social factors, which include overcrowding.