Fewer ESKD dialysis patients (PTS) reach antibody (AB) levels consistent with neutralizing titers when vaccinated with AD26.COV2.S compared with mRNA COVID-19 vaccines

ABSTRACT

Background: The COVID-19 viral vector (VV) vaccine's single dose and routine storage requirements may be preferred to the mRNA-based vaccine's 2 doses and low temperature storage requirements. We report an interim analysis of a quality improvement project performed at 2 Arizona dialysis clinics comparing the AB response to VV vaccine with mRNA vaccine in ESKD pts. Methods: Pts received either the VV vaccine (Ad26.COV2.S) administered in the dialysis clinic or mRNA vaccines (BNT162b2, mRNA-1273) administered in the community. AB response was assessed with remnant blood and a semi-quantitative chemiluminescent assay for IgG directed against the receptor binding domain of the SARS-CoV-2 spike antigen. Values >7.0 Index produce plaque reduction neutralization test (PRNT50) titers greater than 180 dilution recommended by the FDA standard for measuring neutralizing titer. Results: AB response was evaluated at an average of 22 days post vaccination (≥14 days post Ad26.COV2.S or post 2nd mRNA vaccine). 36/45 pts (80%) who received the VV vaccine failed to develop an AB index >7 after ≥14 days post vaccine compared to 5/31 pts (16%) who received an mRNA vaccine (84% achieved AB index >7);all 5 pts had no prior COVID-19 history. Of pts receiving the VV vaccine with prior history of COVID-19, 22% of pts had AB index <8 after 14 days post vaccine. 41 pts receiving the VV vaccine had additional AB measurements in the next 14-37 days (ave 26 days after prior measure). In 34 pts with no prior history of COVID-19, 3 pts achieved AB index >7 in the recent sample and had previously been < 1 (n=1) or 1-7 (n=2), bringing the total number with AB > 7 from 2 to 5 (15%). AB levels remained unchanged in pts with a prior history of COVID-19 (n=9). No demographic or laboratory differences were observed. Conclusions: Our data support the contention that the available VV-based vaccine against the SARS-CoV-2 virus is not effective in producing AB response in most ESKD pts especially when compared to an mRNA counterpart. If AB indices predict immunity and other studies support our findings, alternative vaccination strategies in ESKD pts vaccinated with VV vaccines is needed.