Fig 1.
Study participation flow diagram.
Table 1.
Demographic and clinical characteristics of the sample at Visit 1.
Table 2.
Vaccine status of participants at Visit 3 and Visit 4 following approval for ages 11+ prior to V3 and ages 5–11 prior to V4 using age at time of visit (vaccination considered effective day 14+ post-immunization).
Fig 2.
Participant reallocation between groups from Visit 1 (left-hand side) to Visit 4 (right-hand side).
Participants with SARS-CoV-2 infection prior to enrolment shown in green, participants uninfected at enrolment who remained uninfected in blue, and newly infected participants who acquired SARS-CoV-2 infection between study visits in orange. There were 115 total participant withdrawals in black.
Fig 3.
Study visit collection periods with overlay of COVID-19 pandemic curve.
Date of vaccine availability for children ≥12 (May 10, 2021) indicated by vertical blue line and for children 5–11 years (November 26, 2021) indicated by vertical red line. Main variant of concern indicated by Greek letter α (Alpha B.1.1.7), δ (Delta B.1.617.2), and ο (Omicron B.1.1.529).
Table 3.
Serology results from Visits 1–4 for participants infected prior to enrolment (Group 1) and not infected at enrolment (Group 2).
Table 4.
Visit 3 and Visit 4 serology results stratified by participant age and vaccine status.
Fig 4.
Duration of antibodies in children with confirmed SARS-CoV-2 infection.
(A) Duration of nucleocapsid antibodies in all children from days since AHS-confirmed PCR positive to subsequent serology test(s), n = 500 samples included. (n = 19 re-infections and serology results excluded). (B) Duration of spike antibodies in unvaccinated children from days since AHS-confirmed PCR positive to subsequent serology test(s), n = 306 samples included. (n = 19 samples excluded from re-infections, n = 61 and n = 131 samples excluded at V3 and V4 respectively following vaccination of participants).