Covid-19 vaccine for children: what prospects?

11 Jan, 2021

To date, numerous Covid-19 vaccine trials are underway in adulthood, which have reached different stages, whereas the pediatric age, for which dedicated trials are necessary, has so far been excluded.

Why do children and adolescents need specific studies? What is the current situation? What future prospects?

We asked Dr.ssa Vera Gallo, Pediatrician at the Operating Unit of Pediatric Immunohematology of the San Raffaele Hospital, and Prof. Alessandro Aiuti, Director of the same Unit and Full Professor of Pediatrics at the Vita-Salute San Raffaele University and Director of the School of Specialization in Pediatrics.

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First enrollments for adolescents

Until now, the pediatric age has been excluded from the trials of the Covid-19 vaccine. However, an opening is beginning to take place with the BNT162b2 and mRNA-1273 vaccines produced by Pfizer/BioNtech and Moderna respectively, which have recently extended enrollment to the 12-17 age group [1,2]. The Pfizer/BioNTech vaccine, whose Phase 3 study safety and efficacy results were recently published in the New England Journal of Medicine, has already obtained FDA Emergency Use clearance from 16 years of age and older. The Pfizer/BioNTech vaccine has recently received a positive opinion from EMA and in Italy the vaccination campaign has already begun starting with health professionals.

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Approval for children and adolescents: a dedicated path

However, after the approval of the vaccine for adults, the research path involving children and adolescents is still long. Only the beginning of the large-scale vaccination campaign will provide us with further safety and efficacy data, which will allow us to move to the inclusion of progressively younger children, passing, for example, to children aged 6 to 12, and then to children from 2 to 6 years, and finally to infants and newborns. The development of vaccines in pediatric age, as for any medicinal product, requires ad hoc trials for age groups to determine specific dose, adverse effects and immunogenicity for each group.

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Children are not “small adults”

Children, in fact, cannot be considered simply as small adults, since they differ considerably above all in terms of immunological maturity. An immature immune system, for example, can affect both safety with abnormal immune responses and the effectiveness of the vaccine through an insufficient short or long-term antibody response.

On the basis of current epidemiological data, children do not qualify as category at risk. Most cases are represented by pauci-asymptomatic forms, while the frequency of severe cases and mortality are extremely lower than in adulthood. Some serious but rare forms of multi-systemic inflammatory type (MIS-C) have also been described in children, for which genetic predispositions may exist.

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Clarifying the role of children in community transmission

Therefore, the need to implement and speed up the vaccine testing process also in pediatric age depends very much on the possible role of children in community transmission, which has not yet been fully clarified. While waiting for more data on safety and efficacy on a large scale in adults, it would be desirable to investigate these aspects in depth in order to have definite data on the basis of which to make decisions on the modalities and timing of the experimentation in pediatric age, without forgetting the significant benefits of a safe and effective vaccine that would allow children to be protected and protect others, and not least to regain possession of their childhood.