Effect of a Fourth COVID-19 Vaccine Dose on Omicron Variant Neutralization in Solid Organ Transplant Recipients
American Journal of Transplantation
; 22(Supplement 3):872-873, 2022.
Article
in English
| EMBASE | ID: covidwho-2063469
ABSTRACT
Purpose:
Humoral response to COVID-19 vaccines is attenuated in many solid organ transplant recipients (SOTRs), necessitating additional primary and booster vaccinations. The omicron variant demonstrates substantial immune evasion, and it is not known if boosters increase neutralizing capacity versus omicron among SOTRs. We therefore investigated SOTR antibody response and neutralization versus variants of concern (VOC) including omicron to a 4th vaccine dose (D4). Method(s) Within a national, prospective observational cohort, 25 SOTRs underwent anti-SARS-CoV-2 spike and receptor binding domain (RBD) IgG testing using the Meso Scale Discovery platform before and 2-4 weeks after D4. Surrogate neutralization (%ACE2 inhibition [%ACE2i], range 0-100% with >20% correlating with live virus neutralization), was measured versus full spike proteins of the ancestral ("vaccine") strain and 5 VOCs including delta and omicron. Change in IgG level and %ACE2i were compared using paired Wilcoxon rank-sum testing. Result(s) Demographics are outlined in Table 1, including median (IQR) age 59 (45- 55) years, 64% kidney recipients, and D4 receipt (60% Moderna, 40% Pfizer) median (IQR) 93 days (28-134) post D3. Two participants had SARS-CoV-2 exposure per anti-nucleocapsid testing, including one incident infection. Overall, anti-RBD (92%- >100%) and anti-spike (84%->92%) seropositivity increased after D4, as did median (IQR) anti-spike IgG 42.3 (4.9-134.2)->228.9 (115.4-655.8) WHO binding antibody units (p<0.05). Median (IQR) %ACE2i significantly increased after D4 vs the vaccine strain 5.8% (0-16.8)->20.6% (5.8-45.9) and delta variant 9.1% (4.9-12.8)->17.1% (10.3-31.7) (both p<0.001). In contrast, no SOTR showed neutralization vs omicron before or after D4 median (IQR) %ACE2i 4.1% (0-6.9)->0.5% (0-5.7) (p=0.11). Conclusion(s) Although a 4th vaccine dose increased anti-spike IgG and neutralizing capacity vs some VOC, there was no omicron variant neutralization among SOTRs. SOTRs may remain at high risk for SARS-CoV-2 infection despite boosting, thus additional protective interventions should be urgently explored. (Figure Presented).
adult; antibody response; clinical article; cohort analysis; conference abstract; controlled study; coronavirus disease 2019; demographics; female; gene expression; graft recipient; human; immunoglobulin blood level; kidney; male; middle aged; nonhuman; prospective study; receptor binding; SARS-CoV-2 Omicron; Severe acute respiratory syndrome coronavirus 2; spike; variant of concern; virus neutralization; virus nucleocapsid; endogenous compound; immunoglobulin G; SARS-CoV-2 vaccine; virus spike protein
Full text:
Available
Collection:
Databases of international organizations
Database:
EMBASE
Type of study:
Experimental Studies
Topics:
Vaccines
/
Variants
Language:
English
Journal:
American Journal of Transplantation
Year:
2022
Document Type:
Article
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