Neutralizing antibodies remain 6 months after SARS-CoV-2 infection in kids

A team of researchers from Seattle and the CDC found that neutralizing antibodies remained detectable in most children 6 months after SARS-CoV-2 infection, waning “to a small degree,” according to results presented at IDWeek.

Presenting author Lauren E. Gentles, a graduate student at the Fred Hutchinson Cancer Research Center in Seattle, and colleagues at the center, Seattle Children’s Hospital, the University of Washington and the CDC conducted the research.

Between April 2020 and January 2021, they recruited 32 children aged younger than 18 years — all diagnosed with COVID-19 — for a longitudinal study. In total, 27 of the 32 had no immunocompromised state or comorbidities and 25 of those 27 were symptomatic.

The researchers drew blood samples from participants three times over 62 weeks and examined neutralization titers within the samples.

“When we looked across our entire cohort,” Gentles said, “we found that there was a large degree of variability in the neutralization titers that we measured for each individual. Overall, we saw variable trajectories from individual to individual. But when we looked at an aggregate and the difference between the neutralization titers measure for the first sample compared to the second sample collection, we found that there was no significant difference.”

The results suggest that the neutralization titers are maintained over 6 months following a COVID-19 infection in children, Gentles explained.

“These findings are very interesting because they represent both the functional antibody neutralizing response, and its kinetics, as well as binding antibodies,” Gentles said.

She noted that the study was ongoing, and that samples were still being collected.

“For future studies we think that it's necessary to investigate the longitudinal antibody dynamics in vaccinated children compared to the infection results that we showed here,” Gentles said.

Session moderator Andrew T. Pavia, MD, chief of the division of pediatric infectious diseases at the University of Utah, asked if any of the participants received a COVID-19 vaccine, which is currently approved for children aged 12 years and older, when most of the patients were younger than that age. Gentles answered that they hoped to examine that in future studies.

“The work is ongoing, and I think that a very important question to address is vaccination following infection and how that may boost the antibody response,” Gentles said. “Of course, the majority of participants the participants were under 12, so we'll have to wait for authorization for a vaccine for the younger age group.”