tetano
Editor, Senior Moderator
Nat Med
. 2021 Jun 9.
doi: 10.1038/s41591-021-01410-w. Online ahead of print.
Impact of vaccination on new SARS-CoV-2 infections in the United Kingdom
Emma Pritchard[SUP] 1 2 [/SUP], Philippa C Matthews[SUP] 1 3 4 [/SUP], Nicole Stoesser[SUP] 1 2 3 4 [/SUP], David W Eyre[SUP] 2 3 4 5 [/SUP], Owen Gethings[SUP] 6 [/SUP], Karina-Doris Vihta[SUP] 1 2 [/SUP], Joel Jones[SUP] 6 [/SUP], Thomas House[SUP] 7 8 [/SUP], Harper VanSteenHouse[SUP] 9 10 [/SUP], Iain Bell[SUP] 6 [/SUP], John I Bell[SUP] 11 [/SUP], John N Newton[SUP] 12 [/SUP], Jeremy Farrar[SUP] 13 [/SUP], Ian Diamond[SUP] 6 [/SUP], Emma Rourke[SUP] 6 [/SUP], Ruth Studley[SUP] 6 [/SUP], Derrick Crook[SUP] 1 2 3 4 [/SUP], Tim E A Peto[SUP] 1 2 3 4 [/SUP], A Sarah Walker[SUP] #[/SUP][SUP] 1 2 3 14 [/SUP], Koen B Pouwels[SUP] #[/SUP][SUP] 15 16 17 [/SUP]
Affiliations
Abstract
The effectiveness of COVID-19 vaccination in preventing new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in the general community is still unclear. Here, we used the Office for National Statistics COVID-19 Infection Survey-a large community-based survey of individuals living in randomly selected private households across the United Kingdom-to assess the effectiveness of the BNT162b2 (Pfizer-BioNTech) and ChAdOx1 nCoV-19 (Oxford-AstraZeneca; ChAdOx1) vaccines against any new SARS-CoV-2 PCR-positive tests, split according to self-reported symptoms, cycle threshold value (<30 versus ≥30; as a surrogate for viral load) and gene positivity pattern (compatible with B.1.1.7 or not). Using 1,945,071 real-time PCR results from nose and throat swabs taken from 383,812 participants between 1 December 2020 and 8 May 2021, we found that vaccination with the ChAdOx1 or BNT162b2 vaccines already reduced SARS-CoV-2 infections ≥21 d after the first dose (61% (95% confidence interval (CI) = 54-68%) versus 66% (95% CI = 60-71%), respectively), with greater reductions observed after a second dose (79% (95% CI = 65-88%) versus 80% (95% CI = 73-85%), respectively). The largest reductions were observed for symptomatic infections and/or infections with a higher viral burden. Overall, COVID-19 vaccination reduced the number of new SARS-CoV-2 infections, with the largest benefit received after two vaccinations and against symptomatic and high viral burden infections, and with no evidence of a difference between the BNT162b2 and ChAdOx1 vaccines.
. 2021 Jun 9.
doi: 10.1038/s41591-021-01410-w. Online ahead of print.
Impact of vaccination on new SARS-CoV-2 infections in the United Kingdom
Emma Pritchard[SUP] 1 2 [/SUP], Philippa C Matthews[SUP] 1 3 4 [/SUP], Nicole Stoesser[SUP] 1 2 3 4 [/SUP], David W Eyre[SUP] 2 3 4 5 [/SUP], Owen Gethings[SUP] 6 [/SUP], Karina-Doris Vihta[SUP] 1 2 [/SUP], Joel Jones[SUP] 6 [/SUP], Thomas House[SUP] 7 8 [/SUP], Harper VanSteenHouse[SUP] 9 10 [/SUP], Iain Bell[SUP] 6 [/SUP], John I Bell[SUP] 11 [/SUP], John N Newton[SUP] 12 [/SUP], Jeremy Farrar[SUP] 13 [/SUP], Ian Diamond[SUP] 6 [/SUP], Emma Rourke[SUP] 6 [/SUP], Ruth Studley[SUP] 6 [/SUP], Derrick Crook[SUP] 1 2 3 4 [/SUP], Tim E A Peto[SUP] 1 2 3 4 [/SUP], A Sarah Walker[SUP] #[/SUP][SUP] 1 2 3 14 [/SUP], Koen B Pouwels[SUP] #[/SUP][SUP] 15 16 17 [/SUP]
Affiliations
- PMID: 34108716
- DOI: 10.1038/s41591-021-01410-w
Abstract
The effectiveness of COVID-19 vaccination in preventing new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in the general community is still unclear. Here, we used the Office for National Statistics COVID-19 Infection Survey-a large community-based survey of individuals living in randomly selected private households across the United Kingdom-to assess the effectiveness of the BNT162b2 (Pfizer-BioNTech) and ChAdOx1 nCoV-19 (Oxford-AstraZeneca; ChAdOx1) vaccines against any new SARS-CoV-2 PCR-positive tests, split according to self-reported symptoms, cycle threshold value (<30 versus ≥30; as a surrogate for viral load) and gene positivity pattern (compatible with B.1.1.7 or not). Using 1,945,071 real-time PCR results from nose and throat swabs taken from 383,812 participants between 1 December 2020 and 8 May 2021, we found that vaccination with the ChAdOx1 or BNT162b2 vaccines already reduced SARS-CoV-2 infections ≥21 d after the first dose (61% (95% confidence interval (CI) = 54-68%) versus 66% (95% CI = 60-71%), respectively), with greater reductions observed after a second dose (79% (95% CI = 65-88%) versus 80% (95% CI = 73-85%), respectively). The largest reductions were observed for symptomatic infections and/or infections with a higher viral burden. Overall, COVID-19 vaccination reduced the number of new SARS-CoV-2 infections, with the largest benefit received after two vaccinations and against symptomatic and high viral burden infections, and with no evidence of a difference between the BNT162b2 and ChAdOx1 vaccines.