Without a doubt, young children are the world’s most adorable vectors of disease.<\/p>\n
Their chubby cheeks. Their dimpled knees. Their sticky, unwashed hands and perpetually runny noses. Their tendency to put absolutely everything they can grab into their mouths.<\/p>\n
Anyone who has lived with a toddler or preschooler knows that youngsters are avid collectors of germs. And they can\u2019t help sharing them.<\/p>\n
During the pandemic, a\u00a0new study<\/a> suggests, many older adults were infected with COVID-19 around the time of their grandchildren\u2019s birthdays, probably during parties or family gatherings.<\/p>\n In a study of more than 1.1 million older Danish adults, researchers found that grandparents were 10% more likely to test positive for the coronavirus in the week after a grandchild\u2019s birthday than during other times.\u00a0<\/p>\n The study included almost 1 million grandchildren, whose medical records were linked to those of their grandparents. The study was made possible because of Denmark\u2019s comprehensive national healthcare system, which records every medical or pharmacy visit, as well as the country\u2019s population registry.\u00a0<\/p>\n \u2018Absolutely fascinating\u2019 results<\/p>\n \u201cYou couldn’t do this study anywhere except in Denmark,\u201d said William Schaffner, MD, a\u00a0professor of preventive medicine and infectious diseases at Vanderbilt University School of Medicine, who wasn\u2019t involved in the new study. \u201cIt’s absolutely fascinating.”<\/p>\n A grandparent\u2019s risk of infection was greater if the child celebrating a birthday was in preschool than if the grandchild was older. Grandparents were also at higher risk of developing COVID-19 if they were older than 67, the study showed.<\/p>\n You couldn’t do this study anywhere except in Denmark.<\/p>\n Older people tend to have weaker immune systems than younger adults, Schaffner said. Older adults are also more likely than younger people to have chronic diseases that put them at higher risk of being severely ill with COVID-19.<\/p>\n \u201cIf you think of grandparents and grandchildren, there’s a lot of hugging and kissing and sitting in the lap,\u201d Schaffner told CIDRAP News.<\/p>\n A confetti-covered petri dish<\/p>\n Like other respiratory diseases, COVID-19 spreads best in crowded environments where people are in close contact, especially indoors, said Jennifer Shu, MD, an Atlanta pediatrician not involved in the new study.<\/p>\n Although most children infected with COVID-19 during the pandemic do not become seriously ill, youngsters\u00a0were a significant source of infection<\/a> within households during the pandemic, especially when school was in session, according to a 2023 study.<\/p>\n Children at a party can transmit COVID-19 even if they appear healthy, Shu notes. Youngsters under age 4 years\u00a0are more likely to have asymptomatic COVID-19<\/a> infections than adults, even when their noses are full of viruses.<\/p>\n Studies have long shown that children are adept at spreading germs, from colds and flus to pneumococcal disease, which can cause everything from ear aches to pneumonia. A 2024 study\u00a0found that the biggest risk factor<\/a> for pneumococcal infection in older adults was contact with children.<\/p>\n Pneumococcal infections in older adults often spike during the holidays, possibly because people are infected at family gatherings. In a bit of good news, though, the release of a pneumococcal vaccine for children\u00a0has broken that pattern,<\/a> protecting both kids and their grandparents.<\/p>\n Naive immune systems<\/p>\n