Homologous vaccin-ation with BNT-BNT-BNT generated quantifiable nAbTs against delta and omicron in most IC-HD patients. complex. Most IC-HD individuals are considered fully vaccinated after two doses and boosted after three. Boosting eligibility criteria were finalised on Sept 14, 2021.6 A subset of IC-HD individuals, because of the use of additional immunosuppression (eg, for failed renal transplants) or other comorbidities, are eligible for any three-dose primary program (announced Sept 1, 2021).7 These individuals are already permitted a fourth booster dose 3 months after their third dose. To assess the induction, maintenance, and diversity of nAbs we convened the UK-wide NAOMI consortium study assessing neutralising antibody after COVID-19 vaccination in TNFRSF10D haemodialysis individuals.5 This is an observational multicentre meta-cohort study to compare nAb responses between different vaccine regimens, and in pre-specified patient subgroups. Previously, we compared nAb reactions after two doses of the adenoviral vector OxfordCAstraZeneca vaccine (ChAdOx-1 nCoV-19; AZD1222) or the PfizerCBioNTech mRNA vaccine (BNT162b2). mRNA vaccine neutralising reactions against wildtype disease and VOCs were much like those seen in health-care or laboratory workers.5, 8, 9 Here we report the first nAbTs against omicron in the at-risk IC-HD human population (n=98) a median of 158 days [IQR 146C163] after second dose and 27 days [21C35] after Bithionol third dose. We used live disease microneutralisation assays as previously explained,5 and statement delta like a comparator VOC, with full demographics outlined in the appendix (p 2). First and second doses were either AZD1222 (n=30) or BNT162b2 (n=68). All third doses were BNT162b2 (at full dose). Earlier timepoints from one HD centre have been reported.5 Given the urgency of these data, we locked this first arranged once more than 50 serum samples were available Bithionol after third dose. These individuals were vaccinated from September to November, 2021, and are from two UK HD centres (appendix p 2), reflecting the local variance in the deployment of third doses. First, we assessed nAbTs against omicron and delta at a median of 158 days after two doses of either AZD1222 or BNT162b2 (appendix p 3). After two doses of AZD1222, the median nAbT against either VOC was less than the lower limit of detection of our assay ( 1:40), in keeping with our earlier statement of delta Bithionol nAbTs one month after the second dose5 (omicron IQR 40 to 40; delta IQR 40 to 110). Bithionol At 158 days after two doses of BNT162b2, median nAbTs against delta were 112 (IQR 40 to 342), and median omicron nAbTs were below the range of the assay (appendix p 3; IQR 40 to 157). Next, we regarded as the effect of an additional full Bithionol dose of BNT162b2 (n=50, appendix p 3). For recipients of two doses of AZD1222 followed by a dose of BNT162b2 (AZDCAZDCBNT; n=21), delta nAbTs increased after a third dose to a median of 282 (IQR 40 to 1250). A third dose provided a significant increase in the proportion of patients with this vaccination group with nAbTs above 40 against delta (McNemar’s test p=0023) or omicron (p= 00077). However, the median titres against omicron remained below the quantitative range ( 40 [IQR 40 to 270]). Recipients of three doses of BNT162b2 (BNTCBNTCBNT, n=29) experienced boosted nAbTs against delta, from 112 to 461 (41 fold switch [IQR 171 to 1214]) and developed detectable nAbTs against omicron, having a median nAbT of 236 (IQR 40 to 603) after a third dose. A third dose provided a significant increase in the proportion of patients with this vaccination group with nAbT above 40 against delta (McNemar’s test, p=00077) or omicron (p=00094). For both AZDCZDCBNT and BNTCBNTCBNT.
