COVID antibodies start to decline in kids after only 4 months – study

According to researchers, these findings may indicate that children have a weaker long-term immune response to COVID-19.

This undated transmission electron microscope image shows SARS-CoV-2, also known as novel coronavirus, the virus that causes COVID-19, isolated from a patient in the U.S. Virus particles are shown emerging from the surface of cells cultured in the lab. The spikes on the outer edge of the virus parti (photo credit: NIAID-RML/FILE PHOTO/HANDOUT VIA REUTERS)
This undated transmission electron microscope image shows SARS-CoV-2, also known as novel coronavirus, the virus that causes COVID-19, isolated from a patient in the U.S. Virus particles are shown emerging from the surface of cells cultured in the lab. The spikes on the outer edge of the virus parti
(photo credit: NIAID-RML/FILE PHOTO/HANDOUT VIA REUTERS)
Up to one-third of Jerusalem children were likely infected with coronavirus, according to a soon to be released study performed at Shaare Zedek Medical Center. However, a newly released report by the same hospital indicates that the neutralizing antibodies among youth who catch the virus begin to wane after as little as four months.
A team of doctors at Shaare Zedek, led by Prof. Yechiel Schlesinger, recently completed a first-of-its-kind study in the hospital’s pediatric ward in collaboration with the Health Ministry that showed the prevalence of coronavirus antibodies among children who came to the emergency room for treatment.
The results, according to Schlesinger, “can be used when making policy decisions for the country.”
Specifically, the study that was published in Acta Paediatrica examined 1,138 children under the age of 18, with the mean age of 4.4, between October 18, 2020, and January 12, 2021. It found that of the children who had tested positive for coronavirus during that period, nearly one-third (29%) did not have neutralizing antibodies.
“A third were tested up to three weeks after the onset of the disease and apparently had not yet developed antibodies,” Schlesinger explained. But the other two-thirds had contracted the disease more than four months prior, and it appears that their antibodies had waned.
“The study showed [that children] reach a maximum level of antibodies up to three months after diagnosis,” he said. “Subsequently, a significant quantitative decline in antibodies was observed – more than in adults. These findings may indicate that children have a weaker long-term immune response.”
According to Schlesinger, the disappearance of the antibodies does not mean that these children are not protected, but “it does make you wonder about their protection,” he said. This is especially the case because separate studies have shown a correlation between the likelihood of infection is greater as antibody levels decline.
The study could also have significant implications for understanding herd immunity, for the possibility of a recurrence of a re-infection wave, and for vaccine considerations for young children, he said.
Another interesting finding from the study is that 10% of children were found to have had the virus, although 41% of those children had any known exposure and knew they had been sick.
Schlesinger said that the hospital has been continuing the study and that a subsequent study conducted in June and July 2021, which is being written up now but has still not been published, found that the percentage of children in Jerusalem who had the virus has spiked from 10% to 30% or even slightly higher.

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The Health and Education ministries launched a series of serological testing among students in haredi (ultra-Orthodox) neighborhoods on Monday to determine the percentage of children who might have already had corona. The ministries have suggested that they expect 25% to 30% to have been infected. Those children who do have antibodies will receive a Green Pass and be exempt from entering isolation if a member of their class becomes sick.
Finally, the study showed that the opening of schools did not increase the rates of infection among children, in that there was no over-prevalence of antibodies in children who for various reasons continued to visit educational institutions during the closure periods, compared to children who stayed at home. Moreover, there was no change in morbidity when the country slowly began reopening schools.
“When children came in and they knew they had the disease, we asked them if they knew how they were exposed,” Schlesinger explained. “Only about 10% thought they got it at school.
He stressed that the children involved in the study were kids who came to the emergency room not for COVID but for other reasons, whether pneumonia, a broken toe or appendicitis. Moreover, the study represented a cross section of the population of Jerusalem but does not indicate whether the same thing would be seen in Tel Aviv or Haifa.