Children's Antibody Responses To COVID-19 Stronger Than Adults', Hopkins Study Finds
BALTIMORE (WJZ) -- Young children who experienced COVID-19 infections had much higher levels of antibodies against the virus compared to adults, according to a study by researchers at the Johns Hopkins Bloomberg School of Public Health.
Researchers said the findings could help with effectively immunizing children younger than age 5 against COVID-19.
The study, which was funded by the U.S. Centers of Disease Control and Prevention, differs from earlier reports of low antibody responses in children who had been infected.
Researchers analyzed samples taken from 682 people between 0- and 62-years-old from 175 Maryland households. Those households participated in a surveillance study between November 2020 and March 2021, and none of the participants had been vaccinated.
Researchers found evidence of COVID-19 antibodies in 56 people at the time they enrolled in the study, which indicated previous COVID-19 infection. Of those people, 15 were children ages 0 to 4, and 13 were children ages 5 to 17.
Antibodies to a key site on the virus' "outer spike protein," researchers said, were present at more than 13 times higher in children ages 0-4, and nearly 9 times higher in children age 5-17.
Levels of SARS-CoV-2 neutralizing antibodies, which may be an indicator of protection against severe COVID infection, were nearly twice as high in children ages 0-4 compared to adults, researchers found.
"This study demonstrates that even children in the first few years of life have the capacity to develop strong antibody responses to SARS-CoV-2 infection, which in some cases exceed adult responses," said Ruth Karron, MD, lead investigator and a professor in the Department of International Health and director of the Johns Hopkins Vaccine Initiative at the Bloomberg School.
The school said children younger than 5 years old are a relatively understudied population, and that understanding antibody responses to SARS-CoV-2 at different ages can inform COVID-19 vaccine strategies and policies.
"Very young children in our study developed high titers of antibody to the SARS-CoV-2 spike protein, which is the target antigen for COVID vaccines," Karron said. "These findings should provide some reassurance that with the appropriate vaccine doses we can effectively immunize very young children against SARS-CoV-2."