Antibody Response to ChAdOx1 nCoV-19 (AZD1222) Vaccine in Kidney Transplant Recipients

Abstract

Kidney transplant recipients (KTRs) are at a much higher risk of complications and death following COVID-19 and are poor vaccine responders. The data are limited on the immune response to Covishield® in KTRs. We prospectively recruited a cohort of 67 KTRs aged >18 between April 2021 and December 2021. Each participant was given two intramuscular doses of Covishield®, each of 0.5 mL, at an interval of 12 weeks. A blood specimen of 5.0 mL was collected from each participant at two points within a few days before administering the first dose of the vaccine and at any time between 4–12 weeks after administering the second dose. The sera were tested for anti-RBD antibody (ARAb) titre and neutralising antibody (NAb). An ACE2 competition assay was used as a proxy for virus neutralization. According to the prior COVID-19 infection, participants were grouped as (i) group A: prior symptomatic COVID-19 infection, (ii) group B: prior asymptomatic COVID-19 infection as evidenced by detectable ARAb in the prevaccination specimen, (iii) Group C: no prior infection with COVID-19, (iv) group D: Unclassified, i.e., participants had no symptoms suggestive of COVID-19, but their prevaccination specimen was not available for ARAb testing before vaccination. Fifty of sixty-seven participants (74.6%) provided paired specimens (group A 14, group B 27, and group C 9) and 17 participants (25.4%) provided only postvaccination specimens (group D). In the overall cohort (n = 67), 91% and 77.6% of participants developed ARAb and NAb, respectively. Their ARAb titre and NAb proportion were 2927 (520–7124) U/mL and 87.9 (24.4–93.2) %, respectively. Their median ARAb titre increased 65.6 folds, from 38.2 U/mL to 3137 U/mL. Similarly, the proportion of participants with NAb increased from 56% to 86%, and the NAb proportion raised 2.7 folds, from 23% to 91%. A comparison of vaccine response between the study groups showed that all those with or without prior COVID-19 infection showed a significant rise in ARAb titre (p < 0.05) and NAb proportion (p < 0.05) after the two doses of vaccine administration. The median value of folds rise in anti-RBD and NAb between groups A and B were comparable. Hence, ARAb is present in more than 3/4th of KTRs before the ChAdOx1 vaccine in India. The titer of ARAb and the proportion of NAb significantly increased after the two doses of the ChAdOx1 vaccine in KTRs.

Durability of ChAdOx1 nCoV-19 (Covishield®) Vaccine Induced Antibody Response in Health Care Workers

“…This study also showed a 4 fold rise in ASAb (9786 AU to 38,576 AU) titre after second dose of vaccine. We have previously reported a 36-fold rise in antibody titre after two doses in immunosuppressed renal transplant recipients [ 10 ]. As compared to those who did not have ASAb ( Table 3 ), the booster effect in participants with pre-existing ASAb showed peculiar features of marked booster effect after first dose without additional immune boosting after second dose.…”

“…In India, this vaccine is manufactured by Serum Institute of India (Covishield ® ) and over 1.75 billion doses have been administered to date. The real-life data of Covishield ® shows promising results among HCWs, patients with liver cirrhosis [ 9 ], renal transplant recipients [ 10 ] and those on maintenance hemodialysis [ 11 ].…”

Antibody response to ChAdOx1 nCoV‐19 (Covishield®) vaccine in people on maintenance hemodialysis

“…The participants had received two doses of the vaccineat 13 weeks. 13,14 The 36 pairs of sera, collected after 11 weeks [5][6][7][8][9][10][11][12][13][14][15][16][17][18] of administration of second dose of the vaccine, were tested for ASAb and NAb. Following vaccination, 97% had ASAb and ASAb titer was 9405 (1635-25,000), whereas 83% of participants had NAb and NAb percentage was 96.4% (59.6-98.1%).…”

“…Similarly, high seroprevalence of ASAb has been observed in other group of unvaccinated populations such as health care workers, 16 people with cirrhosis, 17 or renal transplant recipients. 18 An Indian study from a quarantine facility in the state of Karnataka showed that 90% of the infection remains asymptomatic in the community. 19 Further, a high-quality systematic review of 350 studies suggested that nearly 35% of coronavirus infections remain asymptomatic.…”

“…11 (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) Note: Categorical data are presented as number and percentage; numerical data are expressed as median (interquartile range).…”