Abstract
Background: Despite the high level of protection against severe COVID-19 provided by the currently available vaccines some breakthrough infections occur. Until now, there is no information whether a potential risk of a breakthrough infection can be inferred from the level of antibodies after booster vaccination.
Methods: Levels of binding antibodies and neutralization capacity after the first, one and six month after the second, and one month after the third (booster) vaccination against COVID-19 were measured in serum samples from 1391 healthcare workers at the University Hospital Essen. Demographics, vaccination scheme, pre-infection antibody titers and neutralization capacity were compared between individuals with and without breakthrough infections.
Results: The risk of developing an Omicron breakthrough infection was independent of vaccination scheme, sex, body mass index, smoking status or pre-existing conditions. In participants with low pre-infection anti-spike antibodies (≤ 2641.0 BAU/ml) and weaker neutralization capacity (≤ 65.9%) against Omicron one month after the booster vaccination the risk for developing an Omicron infection was 10-fold increased ( P = 0.001; 95% confidence interval, 2.36 – 47.55).
Conclusion: Routine testing of anti-SARS-CoV-2 IgG antibodies and surrogate virus neutralization can quantify vaccine-induced humoral immune response and may help to identify subjects who are at risk for a breakthrough infection. The establishment of thresholds for SARS-CoV-2 IgG antibody levels identifying “non”-, “low” and “high”-responders may be used as an indication for re-vaccination.
Keywords: COVID-19; SARS-CoV-2; anti-spike antibodies; booster vaccination; breakthrough infection; humoral immune response; neutralization.
【저자키워드】 COVID-19, SARS-CoV-2, neutralization, Breakthrough infection, humoral immune response, anti-spike antibodies, booster vaccination, 【초록키워드】 Vaccine, vaccination, severe COVID-19, antibody, neutralization, Infection, Sex, risk, omicron, healthcare worker, immune, body mass index, SARS-CoV-2 IgG antibody, Antibody titer, Virus neutralization, breakthrough infections, threshold, information, university, smoking status, booster, Anti-spike, anti-spike antibody, neutralization capacity, humoral, binding antibody, 95% confidence interval, subject, individual, potential risk, help, participant, routine, serum sample, vaccination against COVID-19, independent, identify, provided, occur, conditions, Level, were measured, anti-SARS-CoV-2 IgG antibody, Essen, 【제목키워드】 prone, omicron, response, individual,