(667) Antibody Response to Sars-Cov-2 Vaccination in Adolescents Following Solid Organ Transplantation

PURPOSE: Serological responses to Covid-19 vaccines in adults post solid organ transplant are impaired [1]. We sought to measure antibodies to SARS-CoV-2 in adolescents post lung, heart, kidney-liver and kidney transplant following the vaccine rollout to 12-17 year-olds in the UK. METHODS: We measured anti-spike, receptor binding domain and nucleocapsid IgG in adolescents attending our centre for routine drug monitoring after Pfizer/BioNTech BNT 162b2 was made available in autumn 2021, and collected information on prior infection from electronic records and via patient/parent recall. RESULTS: Samples were obtained from 42 participants, with paired samples pre and post vaccine in 14 patients. 52% had serological evidence of past exposure at baseline (fig 1). Receptor binding domain IgG was positive in all subjects at follow up, with spike IgG positive in 13/14 (p<0.001, fig 2). Individuals who had received vaccine and been infected had higher levels of spike IgG than those who had been infected and unvaccinated (p<0.05). CONCLUSION: All subjects demonstrated antibody responses to vaccine, and vaccine increases antibody levels in adolescents who have also had a SARS-CoV-2 infection in comparison to the unvaccinated. These data support an age-related relationship to antibody responses in post solid organ transplant recipients and support efforts to increase vaccine uptake in this at-risk group.