Researchers obtained blood samples from 62 children and adolescents hospitalized with severe COVID-19.
Children who previously had COVID-19 or the inflammatory condition MIS-C are not protected from the Omicron version of the coronavirus, according to a study that found vaccination, however, carries the cost of protection. The findings of the study, recently published in the journal Nature Communications, are similar to those found in adults.
“I hear parents say, ‘Oh, my child had COVID last year,'” said senior author of the research paper, Adrienne Randolph of Boston Children’s Hospital, US.
“But we found that antibodies produced by prior infections in children do not neutralize Omicron, meaning that unvaccinated children remain susceptible to Omicron,” Randolph said.
Researchers, including Surendra Khurana of the US Food and Drug Administration, obtained blood samples from 62 children and adolescents hospitalized with severe COVID-19. They also used data from 65 children and adolescents hospitalized with MIS-C and 50 outpatients recovering from mild COVID-19. All samples were taken during 2020 and early 2021, before the emergence of the Omicron variant.
In the laboratory, researchers exposed samples to a pseudovirus, and measured how well the antibodies in the samples were able to neutralize five different SARS-CoV-2 variants of concern: alpha, beta, gamma, delta and Omicron. A pseudovirus is derived from SARS-CoV-2, but its virulence is stripped. Overall, children and adolescents showed some loss of antibody cross-neutralization against all five types, but the loss was most pronounced for Omicron, the researchers said.
Randolph said, “Omicron is very different from previous variants, with multiple mutations on the spike protein, and this work confirms that it is able to evade the antibody response. Unvaccinated children remain susceptible.”
In contrast, children who had received two doses of the COVID-19 vaccine showed higher neutralizing antibody titers against five types, including Omicron. Researchers hope these findings will encourage parents to vaccinate their children and teens.
Read also | COVID: China reports 140 new local cases, Shanghai over 60
Read also | WHO chief Tedros Adhanom says Omicron has made China’s ‘zero-COVID’ policy untenable