High Incidence of SARS-CoV-2 Variant of Concern Breakthrough Infections Despite Residual Humoral and Cellular Immunity Induced by BNT162b2 Vaccination in Healthcare Workers: A Long-Term Follow-Up Study in Belgium.
Bas CalcoenNico CallewaertAline VandenbulckeWinnie KerstensMaya ImbrechtsThomas VercruysseKai DallmeierJohan Van WeyenberghPiet MaesXavier BossuytDorinja ZapfKersten DieckmannKim CallebautHendrik-Jan ThibautKaren VanhoorelbekeSimon F De MeyerWim MaesNick GeukensPublished in: Viruses (2022)
To mitigate the massive COVID-19 burden caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), several vaccination campaigns were initiated. We performed a single-center observational trial to monitor the mid- (3 months) and long-term (10 months) adaptive immune response and to document breakthrough infections (BTI) in healthcare workers ( n = 84) upon BNT162b2 vaccination in a real-world setting. Firstly, serology was determined through immunoassays. Secondly, antibody functionality was analyzed via in vitro binding inhibition and pseudovirus neutralization and circulating receptor-binding domain (RBD)-specific B cells were assessed. Moreover, the induction of SARS-CoV-2-specific T cells was investigated by an interferon-γ release assay combined with flowcytometric profiling of activated CD4 + and CD8 + T cells. Within individuals that did not experience BTI ( n = 62), vaccine-induced humoral and cellular immune responses were not correlated. Interestingly, waning over time was more pronounced within humoral compared to cellular immunity. In particular, 45 of these 62 subjects no longer displayed functional neutralization against the delta variant of concern (VoC) at long-term follow-up. Noteworthily, we reported a high incidence of symptomatic BTI cases (17.11%) caused by alpha and delta VoCs, although vaccine-induced immunity was only slightly reduced compared to subjects without BTI at mid-term follow-up.
Keyphrases
- sars cov
- immune response
- respiratory syndrome coronavirus
- dendritic cells
- coronavirus disease
- high glucose
- risk factors
- diabetic rats
- toll like receptor
- study protocol
- clinical trial
- drug induced
- binding protein
- randomized controlled trial
- high resolution
- inflammatory response
- mass spectrometry
- cross sectional
- stress induced
- childhood cancer