RESUMO
Emergent SARS-CoV-2 variants and waning humoral immunity in vaccinated individuals have resulted in increased infections and hospitalizations. Children are not spared from infection nor complications of COVID-19, and the recent recommendation for boosters in individuals ages 12 years or older calls for broader understanding of the adolescent immune profile after mRNA vaccination. We tested the durability and cross-reactivity of anti-SARS-CoV-2 serologic responses over a six-month time course in vaccinated adolescents against the SARS-CoV-2 wild type and Omicron antigens. Serum from 77 adolescents showed that anti-Spike antibodies wane significantly over 6 months. After completion of a two-vaccine series, cross-reactivity against Omicron-specific receptor-binding domain (RBD) was seen. Evidence of waning mRNA-induced vaccine immunity underscores vulnerabilities in long-term pediatric protection against SARS-CoV-2 infection, while cross-reactivity highlights the additional benefits of vaccination. Characterization of adolescent immune signatures post-vaccination will inform guidance on vaccine platforms and timelines, and ultimately optimize immunoprotection of children.
RESUMO
The rapid spread of the highly mutated SARS-CoV-2 Omicron variant has raised substantial concerns about the protective efficacy of currently available vaccines. We assessed Omicron-specific humoral and cellular immune responses in 65 individuals who were vaccinated with two immunizations of BNT162b2 and were boosted after at least 6 months with either Ad26.COV2.S (Johnson & Johnson; N=41) or BNT162b2 (Pfizer; N=24) (Table S1). O_TBL View this table: org.highwire.dtl.DTLVardef@41c8baorg.highwire.dtl.DTLVardef@e14f5forg.highwire.dtl.DTLVardef@21ea87org.highwire.dtl.DTLVardef@ac4522org.highwire.dtl.DTLVardef@1eed52b_HPS_FORMAT_FIGEXP M_TBL O_FLOATNOTable S1.C_FLOATNO O_TABLECAPTIONCharacteristics of the study population C_TABLECAPTION C_TBL
RESUMO
The introduction of vaccines has inspired new hope in the battle against SARS-CoV-2. However, the emergence of viral variants, in the absence of potent antivirals, has left the world struggling with the uncertain nature of this disease. Antibodies currently represent the strongest correlate of immunity against COVID-19, thus we profiled the earliest humoral signatures in a large cohort of severe and asymptomatic COVID-19 individuals. While a SARS-CoV-2-specific immune response evolved rapidly in survivors of COVID-19, non-survivors exhibited blunted and delayed humoral immune evolution, particularly with respect to S2-specific antibody evolution. Given the conservation of S2 across {beta}-coronaviruses, we found the early development of SARS-CoV-2-specific immunity occurred in tandem with pre-existing common {beta}-coronavirus OC43 humoral immunity in survivors, which was selectively also expanded in individuals that develop paucisymptomatic infection. These data point to the importance of cross-coronavirus immunity as a correlate of protection against COVID-19.
