eprintid: 82890
rev_number: 53
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source: pure
dir: disk0/00/08/28/90
datestamp: 2022-10-24 09:48:02
lastmod: 2024-04-09 03:37:29
status_changed: 2022-10-24 09:48:02
type: article
metadata_visibility: show
creators_name: Kerr, Steven
creators_name: Bedston, Stuart
creators_name: Bradley, Declan T
creators_name: Joy, Mark
creators_name: Lowthian, Emily
creators_name: Mulholland, Rachel M
creators_name: Akbari, Ashley
creators_name: Hobbs, FD Richard
creators_name: Katikireddi, Srinivasa Vittal
creators_name: de Lusignan, Simon
creators_name: Rudan, Igor
creators_name: Torabi, Fatemeh
creators_name: Tsang, Ruby SM
creators_name: Lyons, Ronan A.
creators_name: Robertson, Chris
creators_name: Sheikh, Aziz
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creators_email: chris.robertson@strath.ac.uk
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title: Waning of first- and second-dose ChAdOx1 and BNT162b2 COVID-19 vaccinations : a pooled target trial study of 12.9 million individuals in England, Northern Ireland, Scotland and Wales
ispublished: pub
subjects: QA273
subjects: RA0421
divisions: 178
divisions: 12305
full_text_status: public
abstract: Background:  Several SARS-CoV-2 vaccines have been shown to provide protection against COVID-19 hospitalization and death. However, some evidence suggests that notable waning in effectiveness against these outcomes occurs within months of vaccination. We undertook a pooled analysis across the four nations of the UK to investigate waning in vaccine effectiveness (VE) and relative vaccine effectiveness (rVE) against severe COVID-19 outcomes. Methods:  We carried out a target trial design for first/second doses of ChAdOx1(Oxford–AstraZeneca) and BNT162b2 (Pfizer–BioNTech) with a composite outcome of COVID-19 hospitalization or death over the period 8 December 2020 to 30 June 2021. Exposure groups were matched by age, local authority area and propensity for vaccination. We pooled event counts across the four UK nations. Results:  For Doses 1 and 2 of ChAdOx1 and Dose 1 of BNT162b2, VE/rVE reached zero by approximately Days 60–80 and then went negative. By Day 70, VE/rVE was –25% (95% CI: –80 to 14) and 10% (95% CI: –32 to 39) for Doses 1 and 2 of ChAdOx1, respectively, and 42% (95% CI: 9 to 64) and 53% (95% CI: 26 to 70) for Doses 1 and 2 of BNT162b2, respectively. rVE for Dose 2 of BNT162b2 remained above zero throughout and reached 46% (95% CI: 13 to 67) after 98 days of follow-up. Conclusions:  We found strong evidence of waning in VE/rVE for Doses 1 and 2 of ChAdOx1, as well as Dose 1 of BNT162b2. This evidence may be used to inform policies on timings of additional doses of vaccine.
date: 2023-02-08
date_type: published
publication: International Journal of Epidemiology
volume: 52
number: 1
pagerange: 22–31
pages: 750541
refereed: TRUE
issn: 0300-5771
official_url: https://doi.org/10.1093/ije/dyac199
contact_email_copy: chris.robertson@strath.ac.uk
contact_email: chris.robertson@strath.ac.uk
dates_date: 2023-02-08
dates_date: 2022-10-22
dates_date: 2022-09-30
dates_date_type: published
dates_date_type: published_online
dates_date_type: accepted
citation:   Kerr, Steven and Bedston, Stuart and Bradley, Declan T and Joy, Mark and Lowthian, Emily and Mulholland, Rachel M and Akbari, Ashley and Hobbs, FD Richard and Katikireddi, Srinivasa Vittal and de Lusignan, Simon and Rudan, Igor and Torabi, Fatemeh and Tsang, Ruby SM and Lyons, Ronan A. and Robertson, Chris  and Sheikh, Aziz  (2023 
    ) Waning of first- and second-dose ChAdOx1 and BNT162b2 COVID-19 vaccinations : a pooled target trial study of 12.9 million individuals in England, Northern Ireland, Scotland and Wales.  International Journal of Epidemiology 
     , 52 (1).  22–31.   ISSN 0300-5771     
document_url: https://strathprints.strath.ac.uk/82890/7/Kerr_etal_IJE_2022_Waning_of_first_and_second_dose_ChAdOx1_and_BNT162b2_Covid_19_vaccinations.pdf