Effectiveness of the BNT162b2 (Pfizer-BioNTech) and the ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccines for reducing susceptibility to infection with the Delta variant (B.1.617.2) of SARS-CoV-2



Pattni, Karan, Hungerford, Daniel, Adams, Sarah, Buchan, Iain ORCID: 0000-0003-3392-1650, Cheyne, Christopher, García-Fiñana, Marta, Hall, Ian ORCID: 0000-0002-3033-2335, Hughes, David ORCID: 0000-0002-1287-9994, Overton, Christopher ORCID: 0000-0002-8433-4010, Zhang, Xingna
et al (show 1 more authors) (2021) Effectiveness of the BNT162b2 (Pfizer-BioNTech) and the ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccines for reducing susceptibility to infection with the Delta variant (B.1.617.2) of SARS-CoV-2. [Preprint]

Access the full-text of this item by clicking on the Open Access link.

Abstract

<h4>Background</h4> From January to May 2021 the alpha variant (B.1.1.7) of SARS-CoV-2 was the most commonly detected variant in the UK, but since then the Delta variant (B.1.617.2), first detected in India, has become the predominant variant. The UK COVID-19 vaccination programme started on 8th December 2020. Most vaccine effectiveness studies to date have focused on the alpha variant. We therefore aimed to estimate the effectiveness of the BNT162b2 (Pfizer-BioNTech) and the ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccines in preventing infection with respect to the Delta variant in a UK setting. <h4>Methods</h4> We used anonymised public health record data linked to infection data (PCR) using the Combined Intelligence for Population Health Action resource. We then constructed an SIR epidemic model to explain SARS-CoV-2 infection data across the Cheshire and Merseyside region of the UK. <h4>Results</h4> We determined that the effectiveness of the Oxford-AstraZeneca vaccine in reducing susceptibility to infection is 39% (95% credible interval [34,43]) and 64% (95% credible interval [61,67]) for a single dose and a double dose respectively. For the Pfizer-BioNTech vaccine, the effectiveness is 20% (95% credible interval [10,28]) and 84% (95% credible interval [82,86]) for a single-dose and a double dose respectively. <h4>Conclusion</h4> Vaccine effectiveness for reducing susceptibility to SARS-CoV-2 infection shows noticeable improvement after receiving two doses of either vaccine. Findings also suggest that a full course of the Pfizer-BioNTech provides the optimal protection against infection with the Delta variant. This would advocate for completing the full course programme to maximise individual protection and reduce transmission.

Item Type: Preprint
Uncontrolled Keywords: Coronaviruses Vaccines, Emerging Infectious Diseases, Coronaviruses, Clinical Research, Infectious Diseases, Vaccine Related, Prevention, Immunization, 3.4 Vaccines, 3 Prevention of disease and conditions, and promotion of well-being, Infection, 3 Good Health and Well Being
Divisions: Faculty of Health and Life Sciences
Faculty of Health and Life Sciences > Institute of Infection, Veterinary and Ecological Sciences
Faculty of Health and Life Sciences > Institute of Population Health
Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 19 Oct 2021 15:51
Last Modified: 06 Jun 2024 19:55
DOI: 10.1101/2021.10.12.21264840
Open Access URL: https://www.medrxiv.org/content/10.1101/2021.10.12...
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3140915