Abstract
SARS-CoV-2 Omicron infections are common among individuals who are vaccinated or have recovered from prior variant infection, but few reports have immunologically assessed serial Omicron infections. We characterized SARS-CoV-2 humoral responses in an individual who acquired laboratory-confirmed Omicron BA.1.15 ten weeks after a third dose of BNT162b2, and BA.2 thirteen weeks later. Responses were compared to 124 COVID-19-naive vaccinees. One month post-second and -third vaccine doses, the participant’s wild-type and BA.1-specific IgG, ACE2-displacement and virus neutralization activities were average for a COVID-19-naive triple-vaccinated individual. BA.1 infection boosted the participant’s responses to the cohort ≥95th percentile, but even this strong “hybrid” immunity failed to protect against BA.2. Reinfection increased BA.1 and BA.2-specific responses only modestly. Though vaccines clearly protect against severe disease, results highlight the continued importance of maintaining additional protective measures to counteract the immune-evasive Omicron variant, particularly as vaccine-induced immune responses naturally decline over time.
Keywords: COVID-19; Omicron variant; humoral immunity; reinfection; vaccine.
【저자키워드】 COVID-19, vaccine., Humoral immunity, Reinfection, Omicron variant, 【초록키워드】 SARS-CoV-2, IgG, Vaccine, vaccine doses, Immunity, variant, Infection, omicron, activity, Cohort, infections, Humoral response, response, Virus neutralization, Protective, dose, severe disease, humoral, individual, average, measure, wild-type, vaccinees, vaccine-induced immune response, laboratory-confirmed, highlight, PROTECT, characterized, immunologically, of BNT162b2, 【제목키워드】 omicron, COVID-19 vaccination, infection with SARS-CoV-2,