Changing Epidemiology of COVID-19 in Children and Adolescents Over Four Successive Epidemic Waves in South Africa, 2020–2022

Abstract

Background South Africa experienced four waves of SARS-CoV-2 infection, dominated by Wuhan-Hu, Beta, Delta and Omicron (BA.1/BA.2). We describe the trends in SARS-CoV-2 testing, cases, admissions, and deaths among children and adolescents in South Africa over successive waves. Methods We analysed national SARS-CoV-2 testing, case, and admissions data from March 2020 to February 2022 and estimated cumulative rates by age group for each endpoint. Severity in the third versus the fourth wave was assessed using multivariable logistic regression. Results Individuals ≤18 years comprised 35% (21,008,060/60,142,978) of the population but only 12% (424,394/3,593,644) of cases and 6% (26,176/451,753) of admissions. Among individuals ≤18 years, infants had the highest admission (505/100,000) rates. Testing, case and admission rates generally increased successively in the second (Beta) and third (Delta) waves among all age groups. In the fourth (Omicron BA.1/BA.2) wave the case rate dropped among individuals ≥1-year but increased among those <1-year. Weekly admission rates for children <1-year (169/100,000) exceeded rates in adults (124/100,000) in the fourth wave. The odds of severe COVID-19 in all admitted cases were lower in the fourth wave versus the third wave in each age group, but they were twice as high in admitted cases with at least one comorbidity than those without. Conclusions The admission rate for children <5 years was higher in the fourth wave than previous waves, but the overall outcomes were less severe. However, children with at least one comorbidity had increased odds of severe disease, warranting consideration of prioritising this group for vaccination.

A Review on the Prevalence, Risk Factors, and Management of COVID-19 Disease in South African Children in Comparison to the World

“…The first case of MIS-C in SA was reported in August 2020 in Cape Town [17]. COVID-19 is more prevalent in adults than in children less than 18 years [11,16,18].…”

“…According to WHO, clinical diagnosis depends on disease severity, where (1) non-severe indicates the absence of signs of severe or critical disease, and (2) severe by oxygen saturation less than 90% on room air, signs of pneumonia, or respiratory distress, and (3) critical, the patients require treatment and presents with acute respiratory distress, sepsis, or shock [32]. The laboratory diagnosis of COVID-19 in SA (Table 2) is by using the SARS-CoV-2 reverse-transcription real-time polymerase chain reaction (rRT-PCR) on a respiratory sample obtained from a nasopharyngeal or oropharyngeal swab and SARS-CoV-2 antigen-based testing [10,11,30] 9. Finland BNT162b2 [34] 10.…”

“…The worldwide COVID-19 vaccine nation strategies had initially focused mainly on adults because children were less affected [14]. However, the emergence of mutations in the SARS-CoV-2 genome such as delta and omicron variants increased the risk of infections in children and adolescents in various countries [11,14]. In SA, various variants emerged during the first and fourth waves of the COVID-19 epidemic; the Wuhan-Hu in the first wave between weeks 24 and 34 of 2020, the Beta variant during the second wave between week 47 of 2020 and week 5 of 2021 [11,36].…”

“…However, the emergence of mutations in the SARS-CoV-2 genome such as delta and omicron variants increased the risk of infections in children and adolescents in various countries [11,14]. In SA, various variants emerged during the first and fourth waves of the COVID-19 epidemic; the Wuhan-Hu in the first wave between weeks 24 and 34 of 2020, the Beta variant during the second wave between week 47 of 2020 and week 5 of 2021 [11,36]. The Delta variant caused the third wave between weeks 19 and 37 of 2021, and the omicron variant was responsible for the fourth wave between week 48 of 2021 and week 5 of 2022.…”

“…The FDA has approved the use of the Pfizer-BioNTech COVID-19 vaccine in children aged 5 to 12 years [14,25,26]. Furthermore, SA approved the use of the Pfizer-BioNTech COVID-19 vaccine in children aged 12-17 years on October 20, 2021 (Table 2) [11,14]. The Spikevax vaccine is approved by the European Medicines Agency to be used in adolescents aged 12 to 17 years (Table 2) [34].…”