SARS-CoV-2 spread and hospitalisations in paediatric patients during the omicron surge.

The omicron (B.1.1.529) variant of SARS-CoV-2 was first reported to WHO on Nov 24, 2021, and designated a variant of concern 2 days later. Since then, the variant has been detected in many countries and is causing new surges in the COVID-19 pandemic, which has now lasted for over 2 years. In Europe and the Americas, WHO data indicate that spread of the omicron variant has resulted in 5–6 times more confirmed COVID-19 cases during the reporting weeks of Jan 10 and Jan 17, 2022, compared with highest peaks reported in previous waves. The rapid spread of omicron is attributed to multiple mutations on the spike protein that might have conferred increased host-cell receptor binding affinity and the increased ability to escape immunity induced by COVID-19 vaccination and previous infection. Host-cell analysis using pseudotyped SARS-CoV-2 spike proteins indicated that these mutations might have resulted in the omicron variant being more infectious than the delta (B.1.617.2) variant and other variants of concern.2, 3

In The Lancet Child & Adolescent Health, a study by Jeané Cloete and colleagues, published performed in Tshwane District of South Africa, found a rapid increase in paediatric COVID-19-related admissions to hospital (hereafter, hospitalisations) during the 6-week period from Oct 31 to Dec 11, 2021. The rapid increase in hospitalisations was accompanied by widespread community transmission of the omicron variant, as shown by COVID-19 surveillance data from multiple sources and genomic sequencing data. Although the overall number of COVID-19-associated hospitalisations in Tshwane District were lower than in previous waves, admissions among children and adolescents aged 1 years and younger were higher than at any other time during the pandemic. The authors hypothesise that this increase was due to the higher transmission potential of the omicron variant, less frequent facemask wearing among children than adults, and low vaccination rate in the paediatric population, with only children aged 12 years and older being eligible for vaccination at the time of study.

Among hospitalised paediatric patients (aged ≤13 years) with a primary COVID-19 diagnosis, seizures were reported in 19 (31%) of 138 patients, with only a small number having comorbid conditions (eg, epilepsy [n=1] and cerebral palsy [n=1]) that explained the seizure manifestations. In a separate multinational study of neurological manifestations by Fink and colleagues, seizures were reported in 108 (8·5%) of 1278 children hospitalised with COVID-19. The study included patients from 30 centres across North and South America. Although Fink and colleagues' study predates the omicron wave of the COVID-19 pandemic, it highlighted that seizures were not previously described as a common manifestation of COVID-19 in children. Whether or not seizures, as reported by Cloete and colleagues, are more common with the omicron variant than with the other variants of concern should be further investigated.

Although several studies have shown that the omicron wave is associated with a lower hospitalisation rate per infection than previous COVID-19 waves, primarily because of milder illness, the number of paediatric patients with omicron in many countries is surpassing the number of paediatric COVID-19 cases seen in those previous waves.6, 7, 8 The current study, consistent with previous research, shows the possibility that a large increase in the number of COVID-19 cases, even if milder on average, can increase the absolute number of paediatric patients with severe outcomes. These conditions can overwhelm an already strained health-care system, and be further exacerbated during seasonal increases of expected respiratory illness among children.

The emergence and rapid spread of the omicron variant highlights the need to continue to bolster genomic surveillance of SARS-CoV-2, information sharing among global partners, equitable use of COVID-19 vaccination worldwide, and increased vaccine access for paediatric populations. There is a need to investigate clinical manifestations and severity of infection, including risk factors associated with severe paediatric illness, so that both treatment and prevention measures can be improved. Continuing simultaneous application of public health measures during times of high transmission is essential to minimise the burden of illness among children, including vaccine administration for children, prompt testing and isolation of infected individuals, and wider application of preventive measures such as facemask wearing, hand hygiene, cleaning, and ventilation of indoor spaces.

We declare no competing interests. The findings and conclusions in this Comment are those of the authors and do not necessarily represent the official position of the US Centres for Disease Control and Prevention.