Background Antibodies to Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) have been shown to neutralize the virus in-vitro and prevent disease in animal challenge models upon re-exposure. However, current understanding of SARS-CoV-2 humoral dynamics and longevity is conflicting. Methods The Co-Stars study prospectively enrolled 3679 healthcare workers to comprehensively characterize the kinetics of SARS-CoV-2 spike (S), receptor-binding-domain (RBD) and nucleoprotein (N) antibodies in parallel. Participants screening seropositive had serial monthly serological testing for a maximum of 7 months with the Mesoscale Discovery Assay. Survival analysis determined the proportion of sero-reversion while two hierarchical Gamma models predicted the upper- and lower-bounds of long-term antibody trajectory. Results A total of 1163 monthly samples were provided from 349 seropositive participants. At 200 days post-symptoms, >95% of participants had detectable S-antibodies compared to 75% with detectable N-antibodies. S-antibody was predicted to remain detectable in 95% of participants until 465 days [95%CI 370-575] using a ‘continuous-decay’ model and indefinitely using a ‘decay-to-plateau’ model to account for antibody secretion by long-lived plasma cells. S-antibody titers correlated strongly with surrogate neutralization in-vitro (R 2=0.72). N-antibodies, however, decayed rapidly with a half-life of 60 days [95%CI 52-68]. Conclusions The Co-STAR's study data presented here provides evidence for long-term persistence of neutralizing S-antibodies. This has important implications for the duration of functional immunity following SARS-CoV-2 infection. In contrast, the rapid decay of N-antibodies must be considered in future seroprevalence studies and public health decision-making. This is the first study to establish a mathematical framework capable of predicting long-term humoral dynamics following SARS-CoV-2 infection.

Unaccompanied children (also called unaccompanied minors) are children who have been separated from both parents and other relatives and are not being cared for by an adult who, by law or custom, is responsible for doing so. From 2010 to 2020, unaccompanied minors accounted on average for 15.4% of the total number of first-time asylum applicants aged less than 18 years in the UK. These young people risk their lives and undergo traumatic journeys in search of a better life. However, when they arrive in the UK, they are vulnerable to significant ongoing traumatic experiences.In this review, we look at the reasons young people are forced to flee their countries, how they make their journey, and the risks and dangers they face along the way. We examine safety and victimisation risks faced by children and young people after arrival in the UK, which mechanisms and processes exist to safeguard these individuals, and examine the data available on outcomes of unaccompanied asylum-seeking child (UASC. Finally, we share two case examples that represent both the strengths and weaknesses of existing processes for UASC.