Abstract
Background: There are limited data on immune responses to heterologous COVID-19 immunisation schedules, especially following an extended ≥12-week interval between doses.
Methods: SARS-CoV-2 infection-naïve and previously-infected adults receiving ChAd-BNT (ChAdOx1 nCoV-19, AstraZeneca followed by BNT162b2, Pfizer-BioNTech) or BNT-ChAd as part of the UK national immunisation programme provided blood samples at 30 days and 12 weeks after their second dose. Geometric mean concentrations (GMC) of anti-SARS-CoV-2 spike (S-antibody) and nucleoprotein (N-antibody) IgG antibodies and geometric mean ratios (GMR) were compared with a contemporaneous cohort receiving homologous ChAd-ChAd or BNT-BNT.
Results: During March-October 2021, 75,827 individuals were identified as having received heterologous vaccination, 9,489 invited to participate, 1,836 responded (19.3%) and 656 were eligible. In previously-uninfected adults, S-antibody GMC at 30 days post-second dose were lowest for ChAd-ChAd (862 [95% CI, 694 – 1069]) and significantly higher for ChAd-BNT (6233 [5522–7035]; GMR 6.29; [5.04–7.85]; p<0.001), BNT-ChAd (4776 [4066–5610]; GMR 4.55 [3.56–5.81]; p<0.001) and BNT-BNT (5377 [4596–6289]; GMR 5.66 [4.49–7.15]; p<0.001). By 12 weeks after dose two, S-antibody GMC had declined in all groups and remained significantly lower for ChAd-ChAd compared to ChAd-BNT (GMR 5.12 [3.79–6.92]; p<0.001), BNT-ChAd (GMR 4.1 [2.96–5.69]; p<0.001) and BNT-BNT (GMR 6.06 [4.32–8.50]; p<0.001). Previously infected adults had higher S-antibody GMC compared to infection-naïve adults at all time-points and with all vaccine schedules.
Conclusions: These real-world findings demonstrate heterologous schedules with adenoviral-vector and mRNA vaccines are highly immunogenic and may be recommended after a serious adverse reaction to one vaccine product, or to increase programmatic flexibility where vaccine supplies are constrained.
| Original language | English |
|---|---|
| Pages (from-to) | 692-700 |
| Number of pages | 9 |
| Journal | Journal of Infection |
| Volume | 84 |
| Issue number | 5 |
| Early online date | 4 Feb 2022 |
| DOIs | |
| Publication status | Published - May 2022 |
Bibliographical note
Funding Information: This surveillance was internally funded by Public Health England (now UK Health Security Agency) and did not receive any specific grant funding from agencies in the public, commercial or not-for-profit sectors.SW has previously (2009 –2012) worked on a non-vaccine re- lated clinical study funded by Pfizer Global via an academic insti- tution; the subject area was outside of the submitted work.
Open Access: This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/4.0/ )
Publisher Copyright: Crown Copyright © 2022 Published by Elsevier Ltd on behalf of The British Infection Association.
Citation: Samantha J Westrop, Heather J Whitaker, Annabel A Powell, Linda Power, Corinne Whillock, Helen Campbell, Ruth Simmons, Lenesha Warrener, Mary E Ramsay, Shamez N Ladhani, Kevin E Brown, Gayatri Amirthalingam,
Real-world data on immune responses following heterologous prime-boost COVID-19 vaccination schedule with Pfizer and AstraZeneca vaccines in England,
Journal of Infection, Volume 84, Issue 5, 2022, Pages 692-700, ISSN 0163-4453,
DOI: https://doi.org/10.1016/j.jinf.2022.01.038.
