ABSTRACT
BackgroundThere are presently conflicting data about level and duration of antibodies to SARS-CoV-2 in children after symptomatic or asymptomatic infection. MethodsWe enrolled adults and children in a prospective 6-month study in the following categories: 1) symptomatic, SARS-CoV-2 PCR+ (SP+; children, n=8; adults, n=16), 2) symptomatic, PCR- or untested (children, n=27), 3) asymptomatic exposed (children, n=13) and 4) asymptomatic, no known exposure (children, n=19). Neutralizing and IgG antibodies to SARS-CoV-2 antigens and Spike protein variants were measured by multiplex serological assays. ResultsAll SP+ children developed nAb, whereas 81% of SP+ adults developed nAb. Decline in the presence of nAb over 6 months was not significant in symptomatic children (100% to 87.5%, p=0.32) in contrast to adults (81.3 to 50.0%, p=0.03). Among all children with nAb (n=22), nAb titers and change in titers over 6 months were similar in symptomatic and asymptomatic children. Levels of IgG antibodies in children to the SARS-CoV-2 Spike, RBD-1 and -2, nucleocapsid and N-terminal domain antigens and to Spike protein variants were similar to those in adults. IgG levels to primary antigens decreased over time in both children and adults, but levels to three of six Spike variants decreased only in children. ConclusionsChildren with asymptomatic or symptomatic SARS-CoV-2 infection develop robust neutralizing antibodies that remain present longer than in adults but wane in titer over time, and broad IgG antibodies that also wane in level over time. Key PointsChildren have robust neutralizing and IgG antibody responses to SARS-CoV-2 infection after symptomatic or asymptomatic disease that are at least as strong as in adults. Neutralizing antibodies in children last longer than in adults but wane over time.
ABSTRACT
As the COVID-19 pandemic evolves, and vaccine rollout progresses, the availability and demand for monoclonal antibodies for the prevention and treatment of SARS-CoV-2 infection are also accelerating. This longitudinal serological study evaluated the magnitude and potency of the endogenous antibody response to COVID-19 vaccination in participants who first received a COVID-19 monoclonal antibody in a prevention study. Over the course of six months, serum samples were collected from the prevention population (nursing home residents and staff) enrolled in the BLAZE-2 clinical trial who had received either bamlanivimab (4200 mg) or placebo. In an unplanned component of this trial, a subset of these participants was subsequently fully vaccinated with two doses of either SpikeVax (Moderna) or Comirnaty (BioNTech/Pfizer) COVID-19 mRNA vaccines, as part of the US vaccination program. This post-hoc analysis assessed the immune response to vaccination for the subset of participants (N=135) without prior SARS-CoV-2 infection. Antibody titers and potency were assessed using three assays against SARS-CoV-2 proteins that bamlanivimab does not significantly bind to, thereby reflecting the endogenous antibody response. All bamlanivimab and placebo participants mounted a robust immune response to full COVID-19 vaccination, irrespective of age, risk-category and vaccine type, with any observed differences unlikely to be clinically meaningful. These findings are pertinent for informing public health policy with results that suggest a complementary role for COVID-19 monoclonal antibodies (mAbs) with COVID-19 vaccines and that the benefit of receiving COVID-19 vaccination at the earliest opportunity outweighs the minimal effect on the endogenous immune response due to prior prophylactic COVID-19 mAb infusion. One Sentence SummaryIndividuals infused with an anti-SARS-CoV-2 antibody demonstrated a robust immune response to subsequent full COVID-19 vaccination.
