During the first and second COVID-19 pandemic waves, children, despite susceptible to SARS-CoV-2 infection, appeared at lower risk of severe disease, hospitalization, and death than adults and the elderly. Moreover, they seemed to play a minor role in the diffusion of the virus. The aim of this manuscript is to show epidemiological surveillance on COVID-19 incidence and hospitalization in the pediatric cohort in order to explain the importance of an adequate COVID-19 vaccination coverage in the pediatric population.

All subjects with documented SARS-CoV-2 infection diagnosed in Parma, Italy, between February 21st, 2020, and January, 31st, 2022, were recruited in this epidemiological surveillance. Diagnosis of infection was established in presence of at least one respiratory specimen positive for SARS-CoV-2 nucleic acid using a validated real-time reverse-transcriptase polymerase-chain-reaction (RT-PCR) assay.

The number of COVID-19 pediatric cases remained very low and lower than that recorded in the general population between early February 2020 and the end of October 2021, despite in the last part of this period the Delta variant emerged. On the contrary, starting from November 2021, a sharp and significant increase in COVID-19 incidence in the pediatric population was evidenced. This was detected in all the age groups, although greater in the populations aged 5–11 and 12–17 years old. Interestingly, the peak in hospitalization rate was observed in children < 5 years old, for whom COVID-19 vaccination is not approved yet. At the beginning of November 2021 among people older than 18 years of age 85.7% had completed the primary series of COVID-19 vaccine. Almost all the infants and pre-school children were susceptible. Until January 31st, 2022, 80.4% of adolescents aged 11–17 years had received at least two doses of COVID-19 vaccine and only 52.4% received the booster. Among children 5–11 years old, on January 31st, 2022, only 28.5% had received at least one vaccine dose.

Compared with adults and the elderly, presently a greater proportion of children and adolescents is susceptible to SARS-CoV-2 and could play a relevant role for the prolongation of the COVID-19 pandemic. Only a rapid increase in vaccination coverage of the pediatric populations can effectively counter this problem.