ABSTRACT
AO_SCPLOWBSTRACTC_SCPLOWO_ST_ABSBackgroundC_ST_ABSPatients with cancer, especially haematological cancer, are at increased risk for breakthrough COVID-19 infection. However, so far, a predictive biomarker that can assess compromised vaccine-induced anti-SARS-CoV-2 immunity in cancer patients has not been proposed. MethodsHere, we employed machine learning approaches to identify a biomarker signature based on blood cytokine and growth factors linked to vaccine response from 199 cancer patients receiving BNT162b2 vaccine. ResultsWe show that C-reactive protein (CRP; general marker of inflammation), interleukin (IL)-15 (a pro-inflammatory cytokine), IL-18 (interferon-gamma inducing factor), and placental growth factor (an angiogenic cytokine) can correctly classify patients with a diminished vaccine response assessed at day 49 with >80% accuracy. Amongst these, CRP showed the highest predictive value for poor response to vaccine administration. Importantly, this unique signature of vaccine response was present at different studied timepoints both before and after vaccination and was not majorly affected by different anti-cancer treatments. ConclusionWhile we propose a blood-based signature of cytokines and growth factors that can be employed in identifying cancer patients at continued risk of COVID-19, our data also importantly suggest that such a signature could reflect the inherent make-up of some cancer patients who are also refractive to immunotherapy.
ABSTRACT
BackgroundResidents of nursing homes (NH) are at high risk of COVID-19 related morbidity and death and may respond poorly to vaccination because of old age and frequent comorbidities. MethodsForty residents and forty staff members either naive or previously infected with SARS-CoV-2 were recruited in two NH in Belgium before immunization with two doses of 30{micro}g BNT162b2 mRNA vaccine at day 0 and day 21. Binding antibodies (Ab) to SARS-CoV-2 receptor binding domain (RBD), spike domains S1 and S2, RBD Ab avidity, and neutralizing Ab against SARS-CoV-2 wild type and B.1.351 variant were assessed at days 0, 21, 28, and 49. ResultsSARS-CoV-2 naive residents had lower Ab responses to BNT162b2 mRNA vaccination than naive staff. These poor responses involved lower levels of IgG to all domains of the vaccine antigen, lower avidity of RBD IgG, and lower levels of Ab neutralizing the vaccine strain. No naive resident had detectable neutralizing Ab to the B.1.351 variant. High and comparable Ab responses were observed in residents and staff previously infected with SARS-CoV-2. Clustering analysis revealed that poor vaccine responders not only included naive residents but also naive staff, emphasizing the heterogeneity of responses to mRNA vaccination in the general population. ConclusionsThe poor Ab responses to mRNA vaccination observed in infection naive residents and in some naive staff members of NH suggest suboptimal protection against breakthrough infection, especially with variants of concern. Adapted vaccination regimens may be needed to provide optimal protection against COVID-19 to vulnerable populations. SummaryPoor antibody responses to COVID-19 mRNA vaccination were observed in SARS-CoV-2 infection naive residents and some naive staff members of nursing homes. This suggests suboptimal protection against breakthrough infection, especially with variants of concern, and the need for adapted vaccination regimens.
