KUALA LUMPUR, April 20 – Unvaccinated children aged 5 to 11 made up 87 per cent of kids hospitalised during the Omicron wave and were twice as likely as vaccinated children to be hospitalised for Covid-19, according to a new study released Tuesday by the United States Centers for Disease Control and Prevention (CDC).
The study of 397 children in the US from mid-December last year to late February found that the hospitalisation rate during the Omicron-dominant period was 2.1 times as high among unvaccinated children (19.1 per 100,000 population) as their vaccinated peers (9.2 per 100,000 population).
“The finding that hospitalisation rates in unvaccinated children were double those of vaccinated children suggests that vaccines are effective in preventing Covid-19 associated morbidities.
“This is consistent with recent studies, which suggest that vaccination reduces the risk for Omicron infection, protects against Covid-19 associated illness among children aged 5-11 years and prevents multisystem inflammatory syndrome in children, a severe postinfectious hyperinflammatory condition with a higher incidence in this age group than in other age groups,” researchers said.
Unvaccinated children also stayed longer in the hospital, with a mean hospitalisation length of three days, compared to two days for vaccinated children hospitalised with Covid-19.
Children who completed their primary Covid-19 vaccination series were defined as those who had received the second dose of a two-dose series at least 14 days before receipt of a positive SARS-CoV-2 test result associated with their hospitalisation.
The study also found that while children with diabetes and obesity were more likely to develop severe Covid-19, about a third or 30 per cent of hospitalised children had no underlying medical conditions. One fifth required intensive care unit (ICU) admission.
No vaccinated children who were hospitalised with Covid-19 during the Omicron period required higher level oxygen support, such as the use of high flow nasal oxygen tubes or mechanical ventilation.
However, among unvaccinated children who were hospitalised with Covid-19 during the same Omicron-dominant period, 11 required bilevel positive airway pressure/continuous positive airway pressure (BiPAP/ CPAP), 8 required high flow nasal cannula, and 10 required invasive mechanical ventilation (IMV). No deaths were reported.
“Potential for serious disease requiring hospitalisation, ICU admission, or IMV among children aged 5-11 years reinforces the importance of increasing vaccination coverage among this population,” researchers said.
By ethnicity, black children accounted for the largest proportion of unvaccinated children at 34 per cent and represented approximately one third of Covid-19 associated hospitalisations in this age group.
Researchers said increasing Covid-19 vaccination coverage among children aged 5-11 years, with particular attention to racial and ethnic minority groups disproportionately affected by Covid-19, is critical to reducing Covid-19 associated morbidity.
The CDC-led study analyses data provided by the Covid-19 Associated Hospitalisation Surveillance Network (COVID-NET). COVID-NET conducts population-based surveillance for laboratory-confirmed Covid-19 associated hospitalisations in 99 counties across 14 US states.