Infants, children and adolescents are equally capable of carrying high levels of the virus that causes COVID-19, leaving those ineligible for vaccination more likely to transmit the disease, according to a study published in the Journal of Infectious Diseases.

Researchers who studied 110 subjects from 2 weeks old to 21 years old who tested positive for COVID-19 at Massachusetts General Hospital or urgent care clinics found highest virus levels early during the infection in both asymptomatic or mildly symptomatic kids. Many people assume, incorrectly, that children are less infectious because most experience mild or no symptoms when they develop COVID-19. The viral load, or the amount of virus in respiratory secretions, in children hospitalized with COVID-19 was the same found in hospitalized adults, according to the study. Researchers also found a wide range of potentially more contagious genetic variants in children.

But the viral load had no correlation to the severity of illness, according to researchers at Massachusetts General Hospital, Brigham and Women’s Hospital in Boston, Ragon Institute (Mass General), the Massachusetts Institute of Technology and Harvard.

The Centers for Disease Control and Prevention, in previously released science briefs, has cautioned about COVID-19 spread by children who do not know they are both infected and infectious. But, says the CDC, children are less likely to develop serious illness or die from the virus.

September was the worst month for COVID-19 infections among children, according to the American Academy of Pediatrics, with about 252,000 infections nationwide. More than 6 million children have tested positive for COVID-19 since the pandemic began last year.

The Pfizer-BioNTech vaccine is now available to children 12 and older. The Food and Drug Administration’s vaccine advisory committee is scheduled to meet Oct. 26 to review data submitted by the manufacturer, then decide whether a small dose should be available to the nation’s 28 million children between 5 and 11.

“Regarding the approval process for children ages 5 to 11, we have to allow the FDA its time to review the data and make a decision,” says Dr. Ajay Kumar, Hartford HealthCare’s Chief Clinical Officer. “At this time, I would not want to assume that I have the understanding of all the data. Let the work happen at the FDA and decide what the right next step is. From a societal standpoint, any vaccination we can provide to the larger volume of our citizens is better for us.”

Already, the CDC has distributed a seven-page document with instructions on how to establish expanded vaccination programs.