Two out of three children up to 4 years old in the US have been infected with the coronavirus due to Omicron

At least two in three children aged one to four in the United States are now infected with the coronavirus, according to a US study based on the presence of antibodies in the blood. Infections in this age group – which remains unvaccinated – have increased more than any other this year during the Omicron variant epidemic wave, which, according to scientists, shows its high transmissibility.

Researchers at the Centers for Disease Control and Prevention (CDC), led by epidemiologist Dr. Christy Clark in Atlanta, analyzed antibodies to Covid-19 in blood samples from about 86,000 children and adolescents up to 17 years old, according to Nature. of which 6,100 were up to four years old. In this younger age group it was found in February 2022 that 68% of children (more than two in three) had antibodies against coronavirus, compared to 33% in December 2021, ie in just two months the percentage of young children who had been infected because of Omicron.

The percentage of children aged 5-11 years with antibodies was found to be 77%, while in the age group 12-17 years it was 74%. Based on the Covid-19 cases reported so far in the US, it is estimated that approximately 17% of children under the age of 18 are infected with the coronavirus. But, according to Clark, these figures are only the “tip of the iceberg”, as confirmed – by molecular or rapid test – cases seriously underestimate the true number of infections, especially in very young children, where there are too many asymptomatic and mild infections and in which age groups are rarely tested.

The researchers looked for a specific protein in the blood samples that was not present in the Covid-19 vaccine, so they could tell if the children had acquired antibodies through infection or vaccination.

The number of children under the age of five in need of hospitalization due to Covid-19 was five times higher at the peak of the Omicron wave than in the previous Delta wave, while admissions to a pediatric intensive care unit were 3.5 times higher. Smaller than in Delta. This is partly because, according to Clark, children up to the age of five have not been vaccinated against coronavirus to date, and are less likely to wear a mask and keep their distance from others.

Impressive but not unexpected findings, which show that the spread of infections during Omicron has been underestimated, said vaccine expert Dr. Sabir Mahdi of the South African University of Witwatersrand. He also pointed out that antibody tests can not tell if a person has been infected with the coronavirus more than once, so even these underestimate the true infections.

However, studies to date converge that the risk of severe Covid-19 is lower in children infected with Omicron than in those infected with Delta. Another recent US study, which analyzed data on more than 650,000 children in the United States, comparing admissions to pediatric emergency departments between November 2021 and January 2022, concluded that the risk of serious Omicron disease is about one-third that of what about Delta. Also so far the probability of hospitalization of a child with Covid-19 remains much lower than that of an adult.

Link to the scientific publication: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4092074

SOURCE: ΑΠΕ-ΜΠΕ