key: cord-0920269-ig38pz2m authors: Groves, Helen; Piché‐Renaud, Pierre‐Philippe; Allen, Upton title: The significance and impact of SARS‐CoV‐2 variants of concern in pediatric solid organ transplantation: More unknowns than knowns date: 2021-06-16 journal: Pediatr Transplant DOI: 10.1111/petr.14071 sha: a77d0991416c9d9e2a7aa1bf4efa66ce3dfdd06d doc_id: 920269 cord_uid: ig38pz2m nan The significance and impact of SARS-CoV-2 variants of concern in pediatric solid organ transplantation: More unknowns than knowns The publication by L'huillier et al addresses SARS-CoV-2 infection in pediatric solid organ transplant (SOT) patients and candidates, for which data remain scarce. This work highlights some of the many remaining knowledge gaps with respect to SARS-CoV-2 and pediatric SOT patients. One area of unknown relates to the emergence of new SARS-CoV-2 variants of concern (VOCs) and the potential impact of such variants on immunocompromised children. Key issues with respect to immunocompromised individuals include the genesis of VOCs, their effect on disease severity, transmissibility, and the potential impact on vaccine effectiveness. Spontaneous mutations naturally occur during SARS-CoV-2 viral replication. 1 Evidence from a small number of reports suggests that As highlighted by L'Huillier et al., to date, increased severity of SARS-CoV-2 infection in pediatric SOT recipients has not been described. However, the reports of potentially increased disease severity with some VOCs in immunocompetent populations have emerged. In the United Kingdom (UK), for example, the identified B.1.1.7 lineage has been demonstrated to be associated with a higher mortality rate. 5 In addition, children may be more susceptible to this variant, although the initial reports suggest there is no signal for enhanced severity in the pediatric population. 6 The potential impact of such VOCs on disease severity in pediatric immunocompromised patients, including SOT recipients, is undetermined. Heightened surveillance of the clinical manifestations and disease severity of VOCs in these populations is therefore warranted. Early signals suggest increased transmissibility of some VOCs, including the B.1.1.7, B.1.351, and P.1 lineages. Consistent with the data from the United States, the UK reports on the B.1.1.7 variant suggest a 43 to 90% higher reproduction number versus preexisting variants. 7 It is hypothesized this increased transmissibility may reflect a longer infectious period and increased susceptibility in children, which is of particular concern for immunocompromised pediatric patients, who may therefore be more vulnerable to infection from VOCs. The risk of re-infection with divergent SARS-CoV-2 variants is a point of significant concern worldwide. In Manaus, Brazil, resurgence of COVID-19 despite high seroprevalence may, in part, be due to antigenic escape and re-infection with the P.1 variant. 8 Moreover, although rare, increased disease severity upon re-infection has been Helen Groves and Pierre-Philippe Piché-Renaud are co-first authors. Genetic variants of SARS-CoV-2 -what do they mean? Persistence and evolution of SARS-CoV-2 in an immunocompromised host SARS-CoV-2 evolution during treatment of chronic infection Resistance of SARS-CoV-2 variants to neutralization by monoclonal and serum-derived polyclonal antibodies Risk of mortality in patients infected with SARS-CoV-2 variant of concern 202012/1: matched cohort study Effect of the new SARS-CoV-2 variant B.1.1.7 on children and young people Estimated transmissibility and impact of SARS-CoV-2 lineage B.1.1.7 in England Resurgence of COVID-19 in Manaus, Brazil, despite high seroprevalence Severe reinfection with South African SARS-CoV-2 variant 501Y.V2: a case report Neutralizing activity of BNT162b2-elicited serum Evidence of escape of SARS-CoV-2 variant B.1.351 from natural and vaccine induced sera mRNA vaccine-elicited antibodies to SARS-CoV-2 and circulating variants Immunogenicity of a single dose of SARS-CoV-2 messenger RNA vaccine in solid organ transplant recipients