According to a study published in the journal eClinical Medicine, 17.9 to 81.8%, i.e., the highest seroprevalences in different pandemic waves, were reported in South-East Asia. The study showed that the seroprevalence varied from 7.3% to 37.6% and 56.6% in the first wave of the COVID pandemic to the fifth wave followed by the sixth wave, respectively. It also revealed that globally, 50 to 70% of children under the age of 19 are still susceptible to COVID infection.

The findings of the study were based on a systematic review and meta-analysis of 247 publications containing 302 datasets from international and pre-printed scientific databases conducted to assess SARS-CoV-2 seroprevalence and determinants in children worldwide. The study datasets were taken from 70 countries in the six WHO-defined regions between December 1, 2019, and July 10, 2022.

The study results revealed that omicron led to a significant increase in COVID-19 cases and hospitalizations, especially among children. It also revealed that the reduced risk of infection in the "pre-Omicron" period, combined with concerns about vaccine safety and parental hesitancy, led to limited vaccine uptake and slow implementation of vaccination in children globally, especially among children under 12 years of age.

Additionally, the researchers also revealed that the seroprevalence was found to be higher in children at older ages, in those living in underprivileged countries or regions, and in those of minority ethnic backgrounds. Lastly, they added that the study emphasized the need to develop more effective vaccines and provide better vaccination coverage worldwide.