By studying 110 children aged two weeks to 21 who tested positive for COVID-19 at Massachusetts General Hospital (MGH) or emergency care clinics, researchers confirmed earlier findings that infants, children and adolescents are also able to carry high levels of lifelong, replicating SARS-CoV-2 in their respiratory secretions.
Researchers at Harvard-affiliated MGH and their colleagues at Brigham and Women’s Hospital and the Ragon Institute of MGH, MIT and Harvard then showed that these high levels of viruses correspond to live infectious viruses, and that the levels are highest in onset of disease in both symptomatic and asymptomatic children. They found no correlation between the age of the children and the amount of their viral load.
Researchers have published additional data on several characteristics of the SARS-CoV-2 virus in children in the Journal of Infectious Diseases.
“There had been the question of whether the high viral load in children correlated with the live virus. We have been able to provide a definitive answer that these high viral loads are infectious, ”says Lael Yonker, pediatric pulmonologist at the MGH and co-first author with Julie Boucau, senior scientist at the MGH and the Ragon Institute.
Reassuringly, they also found that the viral load did not correlate with the severity of the disease in the children themselves, but concerns remain for them and those around them: “Children can be carriers of the virus and infect other people, ”says Yonker.
Students and teachers have returned to classrooms, but many questions remain about the impact of the COVID-19 pandemic on children. Most children are asymptomatic or only mildly symptomatic when they develop COVID-19, giving the misconception that children are less contagious. Studying the virological characteristics of SARS-CoV-2 in children with COVID-19 and the difference between SARS-CoV-2 infection and adults is an essential element in establishing effective public health policies , not only to ensure safety within the school. but also to control the pandemic, says Yonker.
As variants of COVID-19 continue to emerge, infected children are potential “reservoirs” for the evolution of new variants as well as potential diffusers of current variants, she says. “Children with COVID-19, even if they are asymptomatic, are infectious and can harbor variants of SARS-CoV-2. The variants could potentially impact both the severity of the disease and the effectiveness of the vaccines, as we see with the Delta variant. When we grew the virus alive, we found a wide variety of genetic variants, ”Yonker adds. “The new variants have the potential to be more contagious and make children sicker.”
Yonker points out that the group’s findings reinforce the importance of masking for children: “The implications of this study show that masking and other public health measures are necessary for everyone – children, adolescents and adults – for us. get out of this pandemic. “
Viral loads in hospitalized children were no different from those found in hospitalized adults, according to the study. Evidence cited by the Centers for Disease Control and Prevention (CDC) suggests that, compared to adults, children “likely have similar viral loads in their nasopharynx, similar secondary infection rates, and can transmit the virus to others “.
Raising awareness of pediatric COVID-19 and implementing broader screening programs for children are two of Yonker’s aspirations. According to the CDC, “The true incidence of SARS-CoV-2 infection in children is not known due to the lack of widespread testing and the prioritization of testing for adults and people with serious illness”.
Yonker adds: “To develop effective public health policies, we need evidence-based public health advice. Children are a critical part of beating the COVID-19 pandemic, and we need to learn more about how they are affected and how they interact with others. “
Co-lead authors are Jonathan Li, director of Harvard / Brigham Specialty Virology Laboratory and Amy Barczak, infectious disease specialist at MGH and Ragon Institute.
The Daily Gazette
Sign up for daily emails to get the latest Harvard news.